The present invention relates to the inhibition of blood clotting proteins, and more particularly, to indole derivatives of the formula I. 
in which R1a, R1b, R1c, R1d, R2, R3, R4 and A are defined as indicated below. The compounds of the formula I are inhibitors of the blood clotting enzyme factor Xa. The invention also relates to processes for the preparation of the compounds of the formula I, to methods of inhibiting factor Xa activity and of inhibiting blood clotting, to the use of the compounds of formula I in the treatment and prophylaxis of diseases which can be cured or prevented by the inhibition of factor Xa activity such as thromboembolic diseases, and to the use of the compounds of formula I in the preparation of medicaments to be applied in such diseases. The invention further relates to compositions containing a compound of the formula I in admixture or otherwise in association with an inert carrier, in particular pharmaceutical compositions containing a compound of the formula I together with pharmaceutically acceptable carrier substances and/or auxiliary substances.
The ability to form blood clots is vital to survival. In certain disease states, however, the formation of blood clots within the circulatory system is itself a source of morbidity. It is nevertheless not desirable in such disease states to completely inhibit the clotting system because life threatening hemorrhage would ensue. In order to reduce the instances of the intravascular formation of blood clots those skilled in the art have endeavored to develop an effective inhibitor of factor Xa, or prothrombinase, the enzyme which is incorporated into the prothrombinase complex where it serves to activate thrombin during clot formation. Appropriate concentrations of such an inhibitor would increase the level of prothrombinase forming agents required to initiate clotting, but would not unduly prolong the clotting process once a threshold concentration of thrombin had been obtained.
Blood coagulation is a complex process involving a progressively amplified series of enzyme activation reactions in which plasma zymogens are sequentially activated by limited proteolysis. Mechanistically the blood coagulation cascade has been divided into intrinsic and extrinsic pathways, which converge at the activation of factor X; subsequent generation of the thrombin proceeds through a single common pathway (see Scheme 1). 
Present evidence suggests that the intrinsic pathway plays an important role in the maintenance and growth of fibrin formation, while the extrinsic pathway is critical in the initiation phase of blood coagulation. It is generally accepted that blood coagulation is physically initiated upon formation of a tissue factor/factor Vila complex. Once formed, this complex rapidly initiates coagulation by activating factors IX and X. The newly generated activated factor X, i.e. factor Xa, then forms a one-to-one complex with factor Va and phospolipids to form a prothrombinase complex, which is responsible for converting soluble fibrinogen to insoluble fibrin via the activation of thrombin from its precursor prothrombin. As time progresses, the activity of the factor VIIa/tissue factor complex (extrinsic pathway) is suppressed by a Kunitz-type protease inhibitor protein, TFPI, which, when complexed to factor Xa, can directly inhibit the proteolytic activity of factor VIIa/tissue factor. In order to maintain the coagulation process in the presence of an inhibited extrinsic system, additional factor Xa is produced via the thrombin-mediated activity of the intrinsic pathway. Thus, thrombin plays a dual autocatalytic role, mediating its own production and the conversion of fibrinogen to fibrin.
The autocatalytic nature of thrombin generation is an important safeguard against uncontrolled bleeding and it ensures that, once a given threshold level of prothrombinase is present, blood coagulation will proceed to completion, effecting, for example, an end of the hemorrhage. Thus, it is most desirable to develop agents that inhibit coagulation without directly inhibiting thrombin. However, despite the long standing recognition of the desirability of such an inhibitor, there is at present no effective specific Xa inhibitor in clinical use.
In many clinical applications there is a great need for the prevention of intravascular blood clots or for some anti-coagulant treatment. The currently available drugs are not satisfactory in many specific clinical applications. For example, nearly 50% of patients who have undergone a total hip replacement develop deep vein thrombosis (DVT). The currently approved therapies are fixed dose low molecular weight heparin (LMWH) and variable dose heparin. Even with these drug regimes 10% to 20% of patients develop DVT and 5% to 10% develop bleeding complications.
Another clinical situation for which better anticoagulants are needed concerns subjects undergoing transluminal coronary angioplasty and subjects at risk for myocardial infarction or suffering from crescendo angina. The present, conventionally accepted therapy, which consists of administering heparin and aspirin, is associated with a 6% to 8% abrupt vessel closure rate within 24 hours of the procedure. The rate of bleeding complications requiring transfusion therapy due to the use of heparin also is approximately 7%. Moreover, even though delayed closures are significant, administration of heparin after termination of the procedures is of little value and can be detrimental.
The most widely used blood-clotting inhibitors are heparin and the related sulfated polysaccharides, LMWH and heparin sulfate. These molecules exert their anti-clotting effects by promoting the binding of a natural regulator of the clotting process, anti-thrombin III, to thrombin and to factor Xa. The inhibitory activity of heparin primarily is directed toward thrombin, which is inactivated approximately 100 times faster than factor Xa. Although relative to heparin, heparin sulfate and LMWH are somewhat more potent inhibitors of Xa than of thrombin, the differences in vitro are modest (3 to 30 fold) and effects in vivo can be inconsequential. Hirudin and hirulog are two additional thrombin-specific anticoagulants presently in clinical trials. However, these anticoagulants, which inhibit thrombin, also are associated with bleeding complications.
Preclinical studies in baboons and dogs have shown that specific inhibitors of factor Xa prevent clot formation without producing the bleeding side effects observed with direct thrombin inhibitors. Such factor Xa inhibitors include, for example, 2,7-bis-(4-amidinobenzylidene)-cycloheptanone and N(xcex1)-tosyl-glycyl-3-amidinophenylaianine methyl ester (xe2x80x9cTENSTOPxe2x80x9d), which have effective inhibitory concentrations (Ki""s) of about 20 nM and 800 nM, respectively. (+)-(2S)-2-(4-({(3S)-1-acetimidoyl-3-pyrrolidinyl}oxy)phenyl)-3-(7-amidino-2-naphthyl)propanoic acid also is representative of a class of factor Xa inhibitors (Katakura et al., Biochem. Biophys. Res. Comm. 197 (1993), 965-972). Thus far, however, these compounds have not been developed clinically.
Several specific inhibitors of factor Xa have been reported. Both synthetic and protein inhibitors of factor Xa have been identified including, for example, antistasin (xe2x80x9cATSxe2x80x9d) and tick anticoagulant peptide (xe2x80x9cTAPxe2x80x9d). ATS, which is isolated from the leech, Haementerin officinalis, contains 119 amino acids and has a Ki for factor Xa of 0.05 nM. TAP, which is isolated from the tick, Ornithodoros moubata, contains 60 amino acids and has a Ki for factor Xa of about 0.5 nM.
The effectiveness of recombinantly-produced ATS and TAP have been investigated in a number of animal model systems. Both inhibitors decrease bleeding time compared to other anticoagulants, and prevent clotting in a thromboplastin-induced, ligated jugular vein model of deep vein thrombosis. The results achieved in this model correlate with results obtained using the current drug of choice, heparin.
Subcutaneous ATS also was found to be an effective treatment in a thromboplastin-induced model of disseminated intravascular coagulation (DIC). TAP effectively prevents xe2x80x9chigh-shearxe2x80x9d arterial thrombosis and xe2x80x9creduced flowxe2x80x9d caused by the surgical placement of a polyester (xe2x80x9cDACRONxe2x80x9d) graft at levels that produced a clinically acceptable prolongation of the activated partial thromboplastin time (aPTT), i.e., less than about two fold prolongation. By comparison, standard heparin, even at doses causing a five fold increase in the aPTT, did not prevent thrombosis and reduced flow within the graft. The aPTT is a clinical assay of coagulation which is particularly sensitive to thrombin inhibitors.
ATS and TAP have not been developed clinically. One major disadvantage of these two inhibitors is that administration of the required repeated doses causes the generation of neutralizing antibodies, thus limiting their potential clinical use. Moreover, the sizes of TAP and ATS render oral administration impossible, further restricting the number of patients able to benefit from these agents.
Other compounds having a factor Xa inhibitory activity have been described. WO-A-95/29 189, for example, discloses factor Xa inhibitors which have a peptide like structure, and WO-A-97/08 165 discloses cyclic guanidines which inhibit factor Xa. In WO-A-97/21 437 naphthyl-substituted benzimidazoles are described which have an inhibitory activity against factor Xa and factor IIa and which can be used as anti-coagulants, and in WO-A-97/30 971 factor Xa inhibitory m-amidino phenyl analogs are described. But there is still a need for further factor Xa inhibitors having improved properties like a favorable pharmacological activity profile.
A specific inhibitor of factor Xa would have substantial practical value in the practice of medicine. In particular, a factor Xa inhibitor would be effective under circumstances where the present drugs of choice, heparin and related sulfated polysaccharides, are ineffective or only marginally effective. Thus, there exists a need for a low molecular weight factor Xa-specific blood clotting inhibitor that is effective, but does not cause unwanted side effects. The present invention satisfies this need by providing novel factor Xa activity inhibiting indole derivatives of the formula I and by providing related advantages as well.
As used herein, the term xe2x80x9cfactor Xa activityxe2x80x9d refers to the ability of factor Xa, by itself or in the assembly of subunits known as the prothrombinase complex, to catalyze the conversion of prothrombin to thrombin. When used in reference to factor Xa activity, the term xe2x80x9cinhibitionxe2x80x9d includes both the direct and indirect inhibition of factor Xa activity. Direct inhibition of factor Xa activity can be accomplished, for example, by the binding of a compound of the formula I to factor Xa or to prothrombinase so as to prevent the binding of prothrombin to the prothrombinase complex active site. Indirect inhibition of factor Xa activity can be accomplished, for example, by the binding of a compound of the invention to soluble factor Xa so as to prevent its assembly into the prothrombinase complex. As used herein, the term xe2x80x9cspecificxe2x80x9d when used in reference to the inhibition of factor Xa activity means that a compound of the formula I can inhibit factor Xa activity without substantially inhibiting the activity of other specified proteases, including plasmin and thrombin (using the same concentration of the inhibitor). Such proteases are involved in the blood coagulation and fibrinolysis cascade. The present invention provides novel compounds which inhibit factor Xa activity but do not substantially inhibit the activity of other proteases involved in the blood coagulation pathway.
Thus, a subject of the present invention are indole derivatives of the formula I, 
wherein
two of the residues R1a, R1b, R1c and R1d independent of one another are hydrogen, F, Cl, Br, I, (C1-C4)-alkyl, CF3, phenyl, phenyl-(C1-C4)-alkyl-, (C1-C4)-alkoxy, phenyloxy-, phenyl-(C1-C4)-alkoxy-, OH, NO2, xe2x80x94NR5aR5b, xe2x80x94NR5bxe2x80x94SO2xe2x80x94R6a, xe2x80x94Sxe2x80x94R6b, xe2x80x94SOnR6c where n is 1 or 2, xe2x80x94SO2xe2x80x94NR5aR5b, xe2x80x94CN or xe2x80x94COxe2x80x94R7, and are identical or different, and the other two of the residues R1a, R1b, R1c and R1d are hydrogen;
R5a is hydrogen, (C1-C4)-alkyl, phenyl, phenyl-(C1-C4)-alkyl-, formyl, ((C1-C4)-alkyl)carbonyl-, phenylcarbonyl-, phenyl-((C1-C4)-alkyl)carbonyl-, ((C1-C4)-alkoxy)carbonyl- or phenyl-((C1-C4)-alkoxy)carbonyl-;
R5b is hydrogen, (C1-C4)-alkyl, phenyl or phenyl-(C1-C4)-alkyl-;
R6a is (C1-C4)-alkyl, phenyl, phenyl-(C1-C4)-alkyl- or phenyl-NH-;
R6b is (C1-C4)-alkyl, phenyl or phenyl-(C1-C4)-alkyl-;
R6c is hydroxy, (C1-C4)-alkyl, phenyl or phenyl-(C1-C4)-alkyl-;
R7 is hydroxy, (C1-C4)-alkoxy, phenyl-(C1-C4)-alkoxy- or xe2x80x94NR5aR5b;
where all residues R5a, R5b, R6a, R6b, R6c and R7 if present more than one time in the molecule, are independent of one another and can each be identical or different;
and where phenyl present in the residues R1a, R1b, R1c, R1d, R5a, R5b, R6a, R6b, R6c and R7 denotes an unsubstituted phenyl residue or a phenyl residue which is substituted by one or two identical or different substituents selected from the series consisting of (C1-C4)-alkyl, F, Cl, Br, CF3, (C1-C4)-alkoxy, NO2, OH, NH2 and CN;
one of the residues R2 and R3 is xe2x80x94(CH2)pxe2x80x94COxe2x80x94R8 and the other is hydrogen, F, Cl, Br, (C1-C4)-alkyl or xe2x80x94(CH2)pxe2x80x94COxe2x80x94R8,
or R2 and R3 together form a group of the formula xe2x80x94CH2xe2x80x94CH2xe2x80x94N(xe2x80x94COxe2x80x94R20)xe2x80x94CH2xe2x80x94 wherein R20 is phenyl, phenyl-(C1-C4)-alkyl-, pyridyl or pyridyl-(C1-C4)-alkyl- and where each phenyl residue is unsubstituted or substituted by R15a and each pyridyl residue is unsubstituted or substituted at the nitrogen atom by R14;
p is 0, 1 or 2;
R8 is xe2x80x94NR9R10, xe2x80x94OR10 or xe2x80x94Sxe2x80x94(C1-C4)-alkyl, where residues R8 if present more than one time in the molecule, are independent of each other and can be identical or different;
R9 is hydrogen, (C1-C4)-alkyl-, hydroxycarbonyl-(C1-C4)-alkyl-, ((C1-C4)-alkoxy)carbonyl-(C1-C4)-alkyl- or aminocarbonyl-(C1-C4)-alkyl-;
R10 is hydrogen, (C1-C10)-alkyl-, phenyl, naphthyl, phenyl-(C1-C4)-alkyl-, naphthyl-(C1-C4)-alkyl-, pyridyl or the residue Het, where the (C1-C10)-alkyl- residue and each phenyl and naphthyl residue is unsubstituted or substituted by one, two or three identical or different residues R11, and where the pyridyl residue is unsubstituted or substituted at the nitrogen atom by R14, and where Het is unsubstituted or substituted by R15a;
or R9 and R10 together with the nitrogen atom to which they are bonded form a 5-membered or 6-membered saturated heterocyclic ring which can contain an additional nitrogen atom in the ring and which is unsubstituted or substituted by R15a or by xe2x80x94COxe2x80x94R7;
Het is the residue of a 5-membered or 6-membered saturated heterocyclic ring containing 1 or 2 identical or different ring heteroatoms selected from the series consisting of nitrogen, oxygen and sulfur;
R11 is xe2x80x94N(R12)2, xe2x80x94OR12, xe2x80x94COxe2x80x94N(R13)2, xe2x80x94COxe2x80x94R7, R15b, (C1-C14)-alkyl, phenyl which is unsubstituted or substituted by one, two or three identical or different residues R15b, naphthyl which is unsubstituted or substituted by one, two or three identical or different residues R15b, quinolinyl which is unsubstituted or substituted by one, two or three identical or different residues R15b and/or substituted at the nitrogen atom by R14, isoquinolinyl which is unsubstituted or substituted by one, two or three identical or different residues R15b and/or substituted at the nitrogen atom by R14, pyridyl which is unsubstituted or substituted at the nitrogen atom by R14, or Het which is unsubstituted or substituted by R15a, where residues R11 if present more than one time in the molecule, are independent of each other and can be identical or different;
each residue R12 independent of the denotation of another residue R12 is hydrogen, (C1-C4)-alkyl, phenyl, phenyl-(C1-C4)-alkyl-, naphthyl, naphthyl-(C1-C4)-alkyl-, pyrrolidinyl, piperidinyl, pyrrolidinyl-(C1-C4)-alkyl- or piperidinyl-(C1-C4)-alkyl-, where each pyrrolidinyl residue and each piperidinyl residue is unsubstituted or substituted at the nitrogen atom by phenyl-(C1-C4)-alkyl- or R15a;
each residue R13 independent of the denotation of another residue R13 is hydrogen, (C1-C4-alkyl, phenyl, phenyl-(C1-C4)-alkyl-, naphthyl or naphthyl-(C1-C4)-alkyl-, or the two residues R13 together with the nitrogen atom to which they are bonded form a 5-membered or 6-membered saturated heterocyclic ring which can contain an additional nitrogen atom or oxygen atom in the ring where the additional nitrogen atom in the ring is unsubstituted or substituted by (C1-C4)-alkyl or phenyl-(C1-C4)-alkyl-;
R14 is (C1-C6)-alkyl, (C1-C6)-alkenyl, (C1-C6)-alkynyl, phenyl-(C1-C6)-alkyl- or ((C1-C8)-alkoxy)carbonyl-(C1-C6)-alkyl-, where phenyl present in R14 denotes an unsubstituted phenyl residue, the substitution by these residues at the nitrogen atom of the heterocyclic residue leading to a positively charged group having Xxe2x88x92 as the counterion; or R14 is oxido this substitution at the nitrogen atom of the heterocyclic residue leading to an N-oxide; and where residues R14 if present more than one time in the molecule, are independent of each other and can be identical or different;
R15a is (C1-C6)-alkyl, ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94, xe2x80x94(CH2)txe2x80x94N(R16)2, xe2x80x94(CH2)txe2x80x94N+(R16a)2(xe2x80x94Oxe2x88x92), xe2x80x94(CH2)txe2x80x94N+(R16a)3Xxe2x88x92, xe2x80x94(CH2)txe2x80x94NHR17, xe2x80x94(CH2)txe2x80x94CN, xe2x80x94(CH2)txe2x80x94CSxe2x80x94N(R18)2, xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 or xe2x80x94(CH2)txe2x80x94NHxe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17, where ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94 is bonded to a ring nitrogen atom, and where residues R15a if present more than one time in the molecule, are independent of each other and can be identical or different;
R15b is (C1-C6)-alkyl, hydroxy, (C1-C4)-alkoxy, F, Cl, Br, I, NO2, xe2x80x94(CH2)txe2x80x94N(R16)2, xe2x80x94(CH2)txe2x80x94N+(R16a)2(xe2x80x94Oxe2x88x92), xe2x80x94(CH2)txe2x80x94N+(R16)3Xxe2x88x92, xe2x80x94(CH2)txe2x80x94NHR17, xe2x80x94(CH2)txe2x80x94COxe2x80x94OR18, xe2x80x94(CH2)txe2x80x94COxe2x80x94N(R18)2, xe2x80x94(CH2)txe2x80x94CN, xe2x80x94(CH2)txe2x80x94CSxe2x80x94N(R18)2, xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 or xe2x80x94(CH2)txe2x80x94NHxe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17, where alkyl can be substituted 1, 2, 3, 4, 5, 6, or 7 times by fluoro, and where residues R15b if present more than one time in the molecule, are independent of each other and can be identical or different;
t is 0, 1, 2 or 3, where numbers t, if present more than one time in the molecule, are independent of each other and can be identical or different;
each residue R16 independent of the denotations of another residue R16 is hydrogen, (C1-C6)-alkyl, (C1-C6)-alkenyl, (C1-C6)-alkynyl, phenyl-(C1-C6)-alkyl- or or ((C1-C6)-alkoxy)carbonyl-(C1-C6)-alkyl-, where phenyl present in R16 denotes an unsubstituted phenyl residue, and where groups containing residues R18 if present more than one time in the molecule, are independent of each other and can be identical or different;
each residue R16a independent of the denotations of another residue R16a is (C1-C6)-alkyl, (C1-C6)-alkenyl, (C1-C6)-alkynyl, phenyl-(C1-C6)-alkyl- or ((C1-C6)-alkoxy)carbonyl-(C1-C6)-alkyl-, where phenyl present in R16a denotes an unsubstituted phenyl residue, and where groups containing residues R16a, if present more than one time in the molecule, are independent of each other and can be identical or different;
each residue R17 independent of the denotation of another residue R17 is hydrogen, (C1-C6)-alkyl, (C1-C6)-alkylcarbonyl-, (C1-C6)-alkoxycarbonyl-, (C1-C6)-alkylcarbonyloxy-(C1-C6)-alkoxycarbonyl-, phenylcarbonyl-, phenoxycarbonyl-, phenyl-(C1-C6)-alkoxycarbonyl-, hydroxy, (C1-C6)-alkoxy, phenyl-(C1-C6)-alkoxy- or amino, and additionally in the groups xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 and xe2x80x94(CH2)txe2x80x94NHxe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 the two residues R17 together with the C(xe2x95x90N)xe2x80x94NH group to which they are bonded, can form a 5-membered or 6-membered heterocyclic ring, and where phenyl present in R17 denotes an unsubstituted phenyl residue, and where groups containing residues R17 if present more than one time in the molecule, are independent of each other and can be identical or different;
each residue R18 independent of the denotation of another residue R18 is hydrogen or (C1-C4)-alkyl;
A is a direct linkage, a divalent xe2x80x94(C1-C4)-alkyl- residue which is saturated or which contains a double bond or a triple bond, xe2x80x94COxe2x80x94, xe2x80x94SOrxe2x80x94 wherein r is 1 or 2, xe2x80x94COxe2x80x94(C1-C4)-alkyl-, xe2x80x94(C1-C4)-alkyl-COxe2x80x94 or xe2x80x94(C1-C4)-alkyl-COxe2x80x94NHxe2x80x94 wherein the nitrogen is bonded to R4;
R4 is phenyl which is substituted by one residue R15c and which can additionally be substituted by one or two substituents from the series consisting of (C1-C4)-alkyl, F, Cl and Br, or R4 is pyridyl which is unsubstituted or substituted at the nitrogen atom by R14, or R4 is the residue Het which is substituted by R15d;
R15c is xe2x80x94(CH2)txe2x80x94N(R16)2, xe2x80x94(CH2)txe2x80x94N+(R16a)2(xe2x80x94Oxe2x88x92), xe2x80x94(CH2)txe2x80x94N+(R16a)3Xxe2x88x92, xe2x80x94(CH2)txe2x80x94NHR17, xe2x80x94(CH2)txe2x80x94CN, xe2x80x94(CH2)txe2x80x94CSxe2x80x94N(R18)2, xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 or xe2x80x94(CH2)txe2x80x94NHxe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17;
R15d is ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94, xe2x80x94(CH2)txe2x80x94N(R16)2, xe2x80x94(CH2)txe2x80x94N+(R16a)2(xe2x80x94Oxe2x88x92), xe2x80x94(CH2)txe2x80x94N+(R16a)3Xxe2x88x92, xe2x80x94(CH2)txe2x80x94NHR17, xe2x80x94(CH2)txe2x80x94CN, xe2x80x94(CH2)txe2x80x94CSxe2x80x94N(R18)2, xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 or xe2x80x94(CH2)txe2x80x94NHxe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17, where ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94 is bonded to a ring nitrogen atom;
Xxe2x88x92 is a physiologically acceptable anion;
in all their stereoisomeric forms and mixtures thereof in any ratio, and their physiologically acceptable salts.
In general, residues or substituents which can occur more than once in compounds of the formula I can all independently of one another have the meanings indicated, and can in all cases be identical or different.
Alkyl residues present in the compounds of the formula I can be straight-chain or branched. This also applies when they carry substituents or occur as substituents in other residues such as, for example, in alkoxy residues, alkylcarbonyl residues, alkoxycarbonyl residues or phenylalkyl residues. An alkyl residue like (C1-C6)-alkyl comprises alkyl residues having 1, 2, 3, 4, 5 or 6 carbon atoms, an alkyl residue like (C1-C6)-alkyl in addition alkyl residues having 7, 8, 9 or 10 carbon atoms, an alkyl residue like (C1-C14)-alkyl in addition alkyl residues having 11, 12, 13 or 14 carbon atoms. Examples of alkyl residues are methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, isopropyl, isobutyl, isopentyl, isohexyl, isooctyl, neopentyl, 3-methylpentyl, sec-butyl, tert-butyl and tert-pentyl. A group of preferred alkyl residues is formed by the residues methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl. Examples of fluoro-substituted alkyl groups are trifluoromethyl, pentafluoroethyl, heptafluoropropyl or 2,2,2-trifluoroethyl, in particular trifluoromethyl.
Further, as used herein, the term alkyl comprises acyclic alkyl residues as well as alkyl residues which contain one or more alicyclic ring system. Thus, in addition to acyclic alkyl residues the term alkyl expressly also comprises cycloalkyl residues which are bonded via a ring carbon atom, and cycloalkyl-alkyl residues which are bonded via a carbon atom in an acyciic subunit. This also applies when alkyl residues carry substituents or occur as substituents in other residues such as, for example, in alkoxy residues, alkylcarbonyl residues, alkoxycarbonyl residues or phenylalkyl residues. Cycloalkyl residues representing alkyl residues or being contained in alkyl residues can be monocyclic or polycyclic, for example monocyclic, bicyclic or tricyclic. Of course, the term alkyl comprises only such cyclic residues which are stable in view of the number of carbon atoms present in the alkyl residue considered. As monocylic alkyl residues have to contain at least three carbon atoms in the ring a (C1-C4)-alkyl residue, for example, comprises also (C3-C4)-monocycloalkyl residues, a (C1-C6)-alkyl residue comprises also (C3-C6)-monocycloalkyl residues, a (C1-C10)-alkyl residue comprises also (C3-C10)-monocycloalkyl residues or a (C1-C14)-alkyl residue comprises also (C3-C14)-monocycloalkyl residues. Bicyclic and tricyclic alkyl residues preferably contain 6, 7, 8, 9, 10, 11, or 12 carbon atoms. Thus, a (C1-C10)-alkyl residue, for example, comprises also (C6-C10)-bicycloalkyl residues and (C6-C10)-tricycloalkyl residues, or a (C1-C14)-alkyl residue comprises also (C6-C14)-bicycloalkyl residues and (C6-C14)-tricycloalkyl residues, both preferably comprising bicycloalkyl residues and tricycloalkyl residues having 7 or more carbon atoms. Examples of cyclic alkyl residues or of alkyl-substituted alkyl residues wherein the alkyl group regarded as a substituent is a cyclic residue, are cyclopropyl, cyclopropylmethyl, cyclopropylethyl, cyclopropylpropyl, cyclopropylbutyl, cyclopropylpentyl, cyclopropylhexyl, cyclopropylheptyl, cyclobutyl, cyclobutylmethyl, cyclobutylethyl, cyclobutylpropyl, cyclobutylbutyl, cyclobutylpentyl, cyclobutylhexyl, cyclopentyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylpropyl, cyclopentylbutyl, cyclopentylpentyl, cyclohexyl, cyclohexyimethyl, cyclohexylethyl, cyclohexylpropyl, cyclohexylbutyl, cycloheptyl, cyclooctyl, octahydroindenyl, bicyclo[4.2.0]octyl, octahydropentalenyl, bicyclo[3.3.1]nonyl, tetradecahydrophenanthryl, dodecahydrophenalenyl, octahydro-1,4-ethano-indenyl, adamantyl or adamantylmethyl, wherein the ethyl, propyl, butyl, pentyl, hexyl and heptyl groups carrying the cyclic groups can be straight-chain or branched as described above. The cyclic groups can be bonded via any suitable carbon atom. Residues derived from bridged hydrocarbons can be bonded via bridgehead carbon atoms or carbon atoms in the bridges. Adamantyl, for example, can be 1-adamantyl or 2-adamantyl.
Alkenyl residues and alkynyl residues can also be straight-chain or branched. Examples of alkenyl residues are vinyl, 1-propenyl, 2-propenyl (=allyl), butenyl, 3-methyl-2-butenyl, pentenyl and hexenyl, examples of alkynyl residues are ethynyl, 1-propynyl, 2-propynyl (=propargyl), butynyl, pentynyl and hexynyl.
The above statements relating to alkyl, alkenyl and alkynyl residues correspondingly apply to divalent alkyl residues, alkenyl residues and alkynyl residues, i.e. to alkylene residues or alkanediyl residues, alkenylene residues or alkenediyl residues and alkynylene residues or alkynediyl residues occurring, for example, in the residue A which can be a divalent alkyl residue which is saturated or contains a double bond or a triple bond. Examples of saturated divalent alkyl residues are methylene (xe2x80x94CH2xe2x80x94), methylmethylene (xe2x80x94CH(CH3)xe2x80x94), dimethylmethylene (xe2x80x94C(CH3)2xe2x80x94), ethylene (xe2x80x94CH2xe2x80x94CH2xe2x80x94), methylethylene (xe2x80x94CH(CH3)xe2x80x94CH2xe2x80x94 and xe2x80x94CH2xe2x80x94CH(CH3)xe2x80x94), trimethylene xe2x80x94(CH2)3xe2x80x94 or tetramethylene xe2x80x94(CH2)4xe2x80x94, examples of unsaturated residues are vinylene (xe2x80x94CHxe2x95x90CHxe2x80x94), 1-propenylene and 2-propenylene (xe2x80x94CHxe2x95x90CHxe2x80x94CH2xe2x80x94 and xe2x80x94CH2xe2x80x94CHxe2x95x90CHxe2x80x94), 2-butenylene (xe2x80x94CH2xe2x80x94CHxe2x95x90CHxe2x80x94CH2xe2x80x94), 2,3-dimethyl-2-butenylene (xe2x80x94CH2xe2x80x94C(CH3)xe2x95x90C(CH3)xe2x80x94CH2xe2x80x94), 1-propynylene and 2-propynylene (xe2x80x94Cxe2x89xa1Cxe2x80x94CH2xe2x80x94 and xe2x80x94CH2xe2x80x94Cxe2x89xa1Cxe2x80x94), or 2-butynylene (xe2x80x94CH2xe2x80x94Cxe2x89xa1Cxe2x80x94CH2xe2x80x94).
In monosubstituted phenyl residues the substituent can be located in the 2-position, the 3-position or the 4-position, with the 3-position and the 4-position being preferred. If phenyl is substituted twice, the substituents can be in the 2,3-position, the 2,4-position, the 2,5-position, the 2,6-position, the 3,4-position or the 3,5-position. In phenyl residues carrying three substituents the substituents can be in the 2,3,4-position, 2,3,5-position, 2,3,6-position, 2,4,5-position, 2,4,6-position, or 3,4,5-position.
Naphthyl residues can be 1-naphthyl and 2-naphthyl. In substituted naphthyl residues the substituents can be in any positions, i.e. in monosubstituted 1-naphthyl residues in the 2-, 3-, 4-, 5-, 6-, 7-, or 8-position and in monosubstituted 2-naphthyl residues in the 1-, 3-, 4-, 5-, 6-, 7-, or 8-position.
Examples of pyridyl residues are 2-pyridyl, 3-pyridyl and 4-pyridyl. Also if a pyridyl residue present in a compound of the formula I is substituted at the nitrogen atom by an oxido group xe2x80x94Oxe2x88x92, i.e. if a pyridine N-oxide residue is present in a compound of the formula I, it can be bonded via the 2-position, the 3-position or the 4-position of the pyridine ring. This also applies to pyridyl residues in which the nitrogen atom is substituted by an alkyl group etc. this substitution leading to a positively charged pyridinium group.
Quinolinyl and isoquinolinyl residues can be 2-, 3-, 4-, 5-, 6-, 7- or 8-quinolinyl and 1-, 3-, 4-, 5-, 6-, 7- or 8-isoquinolinyl, respectively. In substituted quinolinyl and isoquinolinyl residues the substituents can be present in any desired positions, for example in a monosubstituted 4-quinolinyl residue in the 2-, 3-, 5-, 6-, 7- or 8-position and in a monosubstituted 1-isoquinolinyl residue in the 3-, 4-, 5-, 6-, 7- or 8-position. Also if a quinolinyl or isoquinolinyl residue present in a compound of the formula I is substituted at the nitrogen atom by an oxido group xe2x80x94Oxe2x88x92, i.e. if a quinoline or isoquinoline N-oxide residue is present in a compound of the formula I, it can be bonded via any desired position. This also applies to quinolinyl and isoquinolinyl residues in which the nitrogen atom is substituted by an alkyl group etc. this substitution leading to a positively charged quinolinium or isoquinolinium group.
Groups like alkyl groups, phenyl groups, naphthyl groups, quinolinyl groups or isoquinolinyl groups which occur in or which represent groups like R10 or R11 and which can carry as substituents one or more of the groups representing R15b, can preferably carry not more than two, in particular not more than one of the groups xe2x80x94(CH2)txe2x80x94N(R16)2, xe2x80x94(CH2)txe2x80x94N+(R16a)2(xe2x80x94Oxe2x88x92), xe2x80x94(CH2)txe2x80x94N+(R16a)3Xxe2x88x92, xe2x80x94(CH2)txe2x80x94NHR17, xe2x80x94(CH2)txe2x80x94COxe2x80x94OR18, xe2x80x94(CH2)txe2x80x94COxe2x80x94N(R18)2, xe2x80x94(CH2)txe2x80x94CN, xe2x80x94(CH2)txe2x80x94CSxe2x80x94N(R18)2, xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 and xe2x80x94(CH2)txe2x80x94NHxe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17. Of groups like (C1-C6)-alkyl, hydroxy, (C1-C4)-alkoxy, F, Cl, Br, I, NO2, and fluoro-substituted alkyl which can be present as substituents in such alkyl groups, phenyl groups etc., there usually can be present also more than one or more than two groups, for example one, two or three identical or different groups, either in addition to the first listed groups xe2x80x94(CH2)txe2x80x94N(R16)2 etc., or without one of the first listed groups being present.
Unless stated otherwise, aryl groups like phenyl or naphthyl that are present in the compounds of the formula I can in general be unsubstituted or can be substituted in any desired positions by one or more, for example one, two or three, identical or different substituents, for example substituents like (C1-C4)-alkyl such as methyl or tert-butyl, hydroxy, (C1-C4)-alkoxy such as methoxy, ethoxy or tert-butoxy, methylenedioxy, ethylenedioxy, F, Cl, Br, I, cyano, nitro, trifluoromethyl, hydroxymethyl, formyl, acetyl, amino, mono- or di-(C1-C4)-alkylamino, ((C1-C4)-alkyl)carbonylamino, hydroxycarbonyl, ((C1-C4)-alkoxy)carbonyl, carbamoyl, phenyl, benzyl, phenoxy or benzyloxy.
In general, not more than two nitro groups can be present in the compounds of the formula I.
Examples of the 5-membered or 6-membered saturated heterocyclic rings that can be formed by R9 and R10 together with the nitrogen atom to which they are bonded are pyrrolidine, piperidine, pyrazolidine, imidazolidine, hexahydropyrimidine and piperazine. Substituents present in this ring can be bonded to any position unless stated otherwise. Examples of the 5-membered or 6-membered saturated heterocyclic rings that can be formed by the two residues R13 together with the nitrogen atom to which they are bonded are pyrrolidine, piperidine, piperazine or morpholine.
Examples of Het are pyrrolidine, piperidine, perhydroazepine, tetrahydrofuran, perhydropyrane, tetrahydrothiophene, perhydrothiopyran, pyrazolidine, imidazolidine, hexahydropyridazine, hexahydropyrimidine, piperazine, dioxolane, perhydrodioxane, oxazolidine, isoxazolidine, thiazolidine, isothiazolidine, perhydro-1,2-oxazine, perhydro-1,3-oxazine, perhydro-1,4-oxazine (morpholine), perhydro-1,3-thiazine and perhydro-1,4-thiazine (thiomorpholine). Preferred groups Het include, for example, groups containing one nitrogen atom as ring heteroatom like pyrrolidine or piperidine. Substituents present in Het can be bonded to any position unless stated otherwise. A ring nitrogen atom present in Het can carry one or two substituents. When a ring nitrogen atom carries two substituents, i.e. when it is quaternized, it is positively charged, and the compound of the formula I then also comprises an anion Xxe2x88x92 as counterion. In general a group Het can carry one or more than one substituents, for example one, two, three, four or five identical or different substituents. Of the groups representing R15a which can be present as substituents in a group Het, preferably only one or two, in particular not more than one, of the groups ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94, xe2x80x94(CH2)txe2x80x94N(R16)2, xe2x80x94(CH2)txe2x80x94N+(R16a )2(xe2x80x94Oxe2x88x92), xe2x80x94(CH2)txe2x80x94N+(R16a)3Xxe2x88x92, xe2x80x94(CH2)txe2x80x94NHR17, xe2x80x94(CH2)txe2x80x94CN, xe2x80x94(CH2)txe2x80x94CSxe2x80x94N(R18)2, xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 and xe2x80x94(CH2)txe2x80x94NHxe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 can be present as a substituent in Het whereas, for example, (C1-C6)-alkyl substituents can be present once or more than once in Het, for example one, two, three or four times, either without a substituent from the first group being present or in addition to substituents from the first group. Similarly, a group Het representing R4 preferably carries only one of the residues representing R15d. These statements correspondingly apply to substituents in other heterocyclic rings. A group Het and similar heterocyclic groups can in general be substituted by substituents like, for example, (C1-C6)-alkyl groups and also other substituents, for example phenyl-(C1-C4)-alkyl- groups like a benzyl group.
Examples of 5-membered or 6-membered heterocyclic rings which can be formed by two residues R17 together with the C(xe2x95x90N)xe2x80x94NH group to which they are bonded, are 4,5-dihydro-1H-imidazole and 1,4,5,6-tetrahydropyrimidine.
Examples of the substituent ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94 which is attached to the ring nitrogen atom of a heterocycle are the acetimidoyl residue, i.e. the residue CH3xe2x80x94C(xe2x95x90NH)xe2x80x94, or the residues CH3xe2x80x94CH2xe2x80x94C(xe2x95x90NH)xe2x80x94, CH3xe2x80x94CH2xe2x80x94CH2xe2x80x94C(xe2x95x90NH)xe2x80x94 or (CH3)2CHxe2x80x94C(xe2x95x90NH)xe2x80x94.
In the following some groups containing the substituent ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94 are listed which can be present in the residues R2 and/or R3. Similar groups can be present in the residue R4. The following groups correspond to the group R8 in the definition of the compounds of the formula I and are bonded to the CO group in the group xe2x80x94(CH2)pxe2x80x94COxe2x80x94R6 via the nitrogen atom or the oxygen atom having a free bond which is indicated in the following formulae by the line starting from an oxygen atom or an NH group. In the following formulae the substituent ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94 is abbreviated as Aim. 
A residue represented by the formula xe2x80x94(CH2)txe2x80x94N+(R16a)2(xe2x80x94Oxe2x88x92) is the residue of an amine oxide.
Physiologically acceptable anions Xxe2x88x92 which are present in the compounds of the formula I when a positively charged group like a quaternary ammonium group or a pyridinium, quinolinium or isoquinolinium group is present, can be anions derived from suitable inorganic acids or organic carboxylic acids or sulfonic acids. Suitable acids are, in particular, pharmaceutically utilizable or non-toxic acids. Examples of such acids are those given below as examples of acids which can form physiologically acceptable salts with compounds of the formula I containing basic groups. If a compound of the formula I contains an anion Xxe2x88x92 and simultaneously is present as an acid addition salt formed at a basic group, the anion Xxe2x88x92 can be the same as or different from the anion introduced by salt formation.
Physiologically acceptable salts of the compounds of the formula I are, in particular, pharmaceutically utilizable or non-toxic salts. Such salts are formed, for example, from compounds of the formula I which contain acid groups, for example carboxylic acid or sulfonic acid groups. Examples of such salts are salts containing cations of alkali metals or alkaline earth metals, such as, for example, sodium, potassium, magnesium or calcium salts, or salts containing the unsubstituted ammonium cation NH4+ or organic ammonium cations, the latter including cations obtained from physiologically acceptable organic amines, such as, for example, methylamine, ethylamine, triethylamine, ethanolamine, tris(2-hydroxyethyl)amine or amino acids by protonation, and suitable quaternary ammonium cations like, for example, tetramethylammonium.
Compounds of the formula I which contain basic groups, for example one or more amino groups and/or amidino groups and/or guanidino groups, form acid addition salts with, for example, inorganic acids, organic carboxylic acids and organic sulfonic acids. Examples of such acids the anions of which can be present in physiologically acceptable salts of the compounds of formula I are hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, acetic acid, benzoic acid, oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, malic acid, tartaric acid, citric acid, methanesulfonic acid, p-toluenesulfonic acid or naphthalenesulfonic acids.
The present invention also covers inner salts, zwitterions or betaines of the compounds of the formula I.
Physiologically acceptable salts of the compounds of formula I can be prepared according to standard procedures, for example by combining the compound of the formula I with the desired base, for example with an alkaline metal hydroxide or carbonate or hydrogen carbonate or an amine, or with the desired acid in a solvent or diluent. A physiologically acceptable salt of a compound of the formula I can also be prepared from another salt by cation exchange or anion exchange by standard procedures. Moreover, the present invention also covers salts of the compounds of the formula I which are, for example, obtained during the chemical synthesis of the compounds and which are less suitable for the desired use of the compounds of the formula I but which can be used as starting materials for the subsequent preparation of a desired physiologically acceptable salt. The present invention further covers solvates of the compounds of the formula I, for example hydrates or alcoholates.
The compounds of the formula I can be present in stereoisomeric forms. The present invention covers all possible stereoisomers. For example, the compounds of the formula I according to the invention can contain optically active carbon atoms which independently of one another can have R configuration or S configuration. The compounds of the formula I can thus be present in the form of individual enantiomers or individual diastereomers or in the form of enantiomeric mixtures including racemates or diastereomeric mixtures. The present invention relates both to pure enantiomers and mixtures of enantiomers in all ratios, and to pure diastereomers and mixtures of diastereomers in all ratios. The invention covers mixtures of two stereoisomers as well as mixtures of more than two stereoisomers, and all ratios of stereoisomers in the mixtures. The compounds of the formula I can also be present as E isomers or Z isomers (or cis isomers or trans isomers). The present invention relates to both pure E isomers and Z isomers and to mixtures of E isomers and Z isomers in all ratios.
Diastereomers, including E/Z isomers, can be separated into the individual isomers, for example by chromatography. Mixtures of enantiomers including racemates can be separated into the two enantiomers by chromatography on chiral phases or by resolution according to standard procedures like crystallization of diastereomeric salts obtained with auxiliary agents. Stereochemically pure compounds, for example pure enantiomers, can also be obtained by employing into the synthesis optically active starting materials, or by using stereoselective reactions.
The compounds of the formula I according to the invention can further contain mobile hydrogen atoms, i.e. they can be present in various tautomeric forms. The present invention relates to all these tautomers.
The present invention further covers derivatives of the compounds of the formula I in which functional groups are masked or protected by suitable groups, for example by common protective groups. Such functional groups are, for example, carboxylic acid groups which can be present as ester groups or amide groups, or acylatable nitrogen containing groups which can be present as acyl derivatives. The present invention also covers other derivatives and prodrugs of the compounds of the formula I which may be designed in order to enhance the property profile of the compounds of the formula I and which may be prepared according to techniques well known to one skilled in the art, and it covers active metabolites of the compounds of the formula I.
A specific group of compounds of the formula I is formed by those compounds wherein two of the residues R1a, R1b, R1c and R1d independently of each other are hydrogen, F, Cl, Br, I, (C1-C4)-alkyl, CF3, phenyl, phenyl-(C1-C4)-alkyl-, (C1-C4)-alkoxy, phenyloxy-, phenyl-(C1-C4)-alkoxy-, OH, NO2, xe2x80x94NR5aR5b, xe2x80x94NR5bxe2x80x94SO2xe2x80x94R6a, xe2x80x94Sxe2x80x94R6b, xe2x80x94SOnxe2x80x94R6c where n is 1 or 2, xe2x80x94SO2xe2x80x94NR5aR5b, xe2x80x94CN or xe2x80x94COxe2x80x94R7, and the other two of the residues R1a, R1b, R1c and R1d are hydrogen;
R5a is hydrogen, (C1-C4)-alkyl, phenyl, phenyl-(C1-C4)-alkyl-, formyl, ((C1-C4)-alkyl)carbonyl-, phenylcarbonyl-, phenyl-((C1-C4)-alkyl)carbonyl-, ((C1-C4)-alkoxy)carbonyl- or phenyl-((C1-C4)-alkoxy)carbonyl-;
R5b is hydrogen, (C1-C4)-alkyl, phenyl or phenyl-(C1-C4)-alkyl-;
R6a is (C1-C4)-alkyl, phenyl, phenyl-(C1-C4)-alkyl- or phenyl-NHxe2x80x94;
R6b is (C1-C4)-alkyl, phenyl or phenyl-(C1-C4)-alkyl-;
R6c is hydroxy, (C1-C4)-alkyl, phenyl or phenyl-(C1-C4)-alkyl-;
R7 is hydroxy, (C1-C4)-alkoxy, phenyl-(C1-C4)-alkoxy- or xe2x80x94NR5aR5b;
where all residues R5a, R5b, R6a, R6b, R6c and R7 if present more than one time in the molecule, are independent of one another and can each be identical or different;
phenyl present in the residues R1a, R1b, R1c, R1d, R5a, R5b, R6a, R6b, R6c and R7 denotes an unsubstituted phenyl residue or a phenyl residue which is substituted by one or two substituents selected from the series consisting of (C1-C4)-alkyl, F, Cl, Br, CF3, (C1-C4)-alkoxy, NO2, OH, NH2 and CN;
one of the residues R2 and R3 is xe2x80x94(CH2)pxe2x80x94COxe2x80x94R8 and the other is hydrogen, F, Cl, Br, (C1-C4)-alkyl or xe2x80x94(CH2)pxe2x80x94COxe2x80x94R8,
or R2 and R3 together form a group of the formula xe2x80x94CH2xe2x80x94CH2xe2x80x94N(xe2x80x94COxe2x80x94R20)xe2x80x94CH2xe2x80x94 wherein R20 is phenyl, phenyl-(C1-C4)-alkyl-, pyridyl or pyridyl-(C1-C4)-alkyl- and where each phenyl residue is unsubstituted or substituted by R15a and each pyridyl residue is unsubstituted or substituted at the nitrogen atom by R14;
p is 0, 1 or 2;
R8 is xe2x80x94NR9R10 or xe2x80x94OR10, where residues R8 if present more than one time in the molecule, are independent of each other and can be identical or different;
R9 is hydrogen, (C1-C4)-alkyl-, hydroxycarbonyl-(C1-C4)-alkyl-, ((C1-C4)-alkoxy)carbonyl-(C1-C4)-alkyl- or aminocarbonyl-(C1-C4)-alkyl-;
R10 is hydrogen, (C1-C8)-alkyl-, phenyl, naphthyl, phenyl-(C1-C4)-alkyl-, naphthyl-(C1-C4)-alkyl-, pyridyl or the residue Het, where the (C1-C8)-alkyl- residue residue and each phenyl and naphthyl residue is unsubstituted or substituted by one or two identical or different residues R11, and where the pyridyl residue is unsubstituted or substituted at the nitrogen atom by R14, and where Het is unsubstituted or substituted by R15a;
or R9 and R10 together with the nitrogen atom to which they are bonded form a 5-membered or 6-membered saturated heterocyclic ring which can contain an additional nitrogen atom in the ring and which is unsubstituted or substituted by R15a or by xe2x80x94COxe2x80x94R7;
Het is the residue of a 5-membered or 6-membered saturated heterocyclic ring containing 1 or 2 identical or different ring heteroatoms selected from the series consisting of nitrogen, oxygen and sulfur;
R11 is xe2x80x94NHR12, xe2x80x94OR12, xe2x80x94COxe2x80x94N(R13)2, xe2x80x94COxe2x80x94R7, R15b, cyclohexyl, phenyl which is unsubstituted or substituted by R15b, naphthyl which is unsubstituted or substituted by R15b, pyridyl which is unsubstituted or substituted at the nitrogen atom by R14, or Het which is unsubstituted or substituted by R15a, where residues R11 if present more than one time in the molecule, are independent of each other and can be identical or different;
R12 is hydrogen, pyrrolidinyl, piperidinyl, pyrrolidinyl-(C1-C4)-alkyl- or piperidinyl-(C1-C4)-alkyl-, where each pyrrolidinyl residue and each piperidinyl residue is unsubstituted or substituted at the nitrogen atom by phenyl-(C1-C4)-alkyl- or R15a;
each residue R13 independently of the denotation of another residue R13 is hydrogen, (C1-C4)-alkyl or phenyl-(C1-C4)-alkyl-, or the two residues R13 together with the nitrogen atom to which they are bonded form a 5-membered or 6-membered saturated heterocyclic ring which can contain an additional nitrogen atom or oxygen atom in the ring where the additional nitrogen atom in the ring is unsubstituted or substituted by (C1-C4)-alkyl or phenyl-(C1-C4)-alkyl-;
R14 is (C1-C6)-alkyl, (C1-C6)-alkenyl, (C1-C6)-alkynyl, phenyl-(C1-C6)-alkyl or ((C1-C6)-alkoxy)carbonyl-(C1-C6)-alkyl-, where phenyl present in R14 denotes an unsubstituted phenyl residue, the substitution by these residues at the nitrogen atom of the pyridyl residue leading to a pyridinium group having Xxe2x88x92 as the counterion; or R14 is oxido this substitution at the nitrogen atom of the pyridyl residue leading to a pyridine N-oxide; and where residues R14 if present more than one time in the molecule, are independent of each other and can be identical or different;
R15a is (C1-C6)-alkyl, ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94, xe2x80x94(CH2)txe2x80x94N(R16)2, xe2x80x94(CH2)txe2x80x94N+(R16a)2(xe2x80x94Oxe2x88x92), xe2x80x94(CH2)txe2x80x94N+(R16a)3Xxe2x88x92, xe2x80x94(CH2)txe2x80x94NHR17, xe2x80x94(CH2)txe2x80x94CN, xe2x80x94(CH2)txe2x80x94CSxe2x80x94N(R18)2, xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 or xe2x80x94(CH2)txe2x80x94NHxe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17, where ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94 is bonded to a ring nitrogen atom, and where residues R15a if present more than one time in the molecule, are independent of each other and can be identical or different;
R15b is (C1-C6)-alkyl, hydroxy, F, Cl, Br, xe2x80x94(CH2), xe2x80x94N(R16)2, xe2x80x94(CH2)txe2x80x94N+(R16a)2(xe2x80x94Oxe2x88x92) xe2x80x94(CH2)txe2x80x94N+(R16a)3Xxe2x88x92, xe2x80x94(CH2)txe2x80x94NHR17, xe2x80x94(CH2)txe2x80x94CN, xe2x80x94(CH2)txe2x80x94CSxe2x80x94N(R18)2, xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 or xe2x80x94(CH2)txe2x80x94NHxe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17, where residues R15b if present more than one time in the molecule, are independent of each other and can be identical or different;
t is 0, 1, 2 or 3, where numbers t, if present more than one time in the molecule, are independent of each other and can be identical or different;
each residue R16 independently of the denotations of another residue R16 is hydrogen, (C1-C6)-alkyl, (C1-C6)-alkenyl, (C1-C6)-alkynyl, phenyl-(C1-C6)-alkyl- or ((C1-C6)-alkoxy)carbonyl-(C1-C6)-alkyl-, where phenyl present in R16 denotes an unsubstituted phenyl residue, and where groups containing residues R16 if present more than one time in the molecule, are independent of each other and can be identical or different;
each residue R16a independently of the denotations of another residue R16a is (C1-C6)-alkyl, (C1-C6)-alkenyl, (C1-C6)-alkynyl, phenyl-(C1-C6)-alkyl- or ((C1-C6)-alkoxy)carbonyl-(C1-C6)-alkyl-, where phenyl present in R16a denotes an unsubstituted phenyl residue, and where groups containing residues R16a if present more than one time in the molecule, are independent of each other and can be identical or different;
each residue R17 independently of the denotation of another residue R17 is hydrogen, (C1-C6)-alkyl, (C1-C6)-alkylcarbonyl-, (C1-C6)-alkoxycarbonyl-, (C1-C6)-alkylcarbonyloxy-(C1-C6)-alkoxycarbonyl-, phenylcarbonyl-, phenoxycarbonyl-, phenyl-(C1-C6)-alkoxycarbonyl-, hydroxy, (C1-C6)-alkoxy, phenyl-(C1-C6)-alkoxy- or amino, and additionally in the groups xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 and xe2x80x94(CH2)txe2x80x94NHxe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 the two residues R17 together with the C(xe2x95x90N)xe2x80x94NH group to which they are bonded, can form a 5-membered or 6-membered heterocyclic ring, and were phenyl present in R17 denotes an unsubstituted phenyl residue, and where groups containing residues R17 if present more than one time in the molecule, are independent of each other and can be identical or different;
each residue R18 independently of the denotation of another residue R18 is hydrogen or (C1-C4)-alkyl;
A is a direct linkage, xe2x80x94(C1-C4)-alkyl- which is saturated or which contains a double bond or a triple bond, xe2x80x94COxe2x80x94, xe2x80x94SOrxe2x80x94 wherein r is 1 or 2, xe2x80x94COxe2x80x94(C1-C4)-alkyl-, xe2x80x94(C1-C4)-alkyl-COxe2x80x94 or xe2x80x94(C1-C4)-alkyl-COxe2x80x94NHxe2x80x94 wherein the nitrogen is bonded to R4;
R4 is phenyl which is substituted by R15c and which additionally can be substituted by one or two substituents from the series consisting of (C1-C4)-alkyl, F, Cl and Br, or R4 is pyridyl which is unsubstituted or substituted at the nitrogen atom by R14, or R4 is the residue Het which is substituted by R15d;
R15c is xe2x80x94(CH2)txe2x80x94N(R16)2, xe2x80x94(CH2)txe2x80x94N+(R16a)2(xe2x80x94Oxe2x88x92), xe2x80x94(CH2)txe2x80x94N+(R16a)3Xxe2x88x92, xe2x80x94(CH2)txe2x80x94NHR17, xe2x80x94(CH2)txe2x80x94CN, xe2x80x94(CH2)txe2x80x94CSxe2x80x94N(R18)2, xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 or xe2x80x94(CH2)txe2x80x94NHxe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17;
R15d is ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94, xe2x80x94(CH2)txe2x80x94N(R16)2, xe2x80x94(CH2)txe2x80x94N+(R16a)2(xe2x80x94Oxe2x88x92), xe2x80x94(CH2)txe2x80x94N+(R16a)3Xxe2x88x92, xe2x80x94(CH2)txe2x80x94NHR17, xe2x80x94(CH2)txe2x80x94CN, xe2x80x94(CH2)txe2x80x94CSxe2x80x94N(R18)2, xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 or xe2x80x94(CH2)txe2x80x94NHxe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17, where ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94 is bonded to a ring nitrogen atom;
Xxe2x88x92 is a physiologically acceptable anion;
in all their stereoisomeric forms and mixtures thereof in any ratio, and their physiologically acceptable salts.
As with any group of structurally related compounds which possess a particular generic utility, certain groups and configurations are preferred for compounds of the formula I in their end-use application.
Preferred compounds of the formula I are those wherein the residues R1a, R1b, R1c and R1d independently of one another are selected from the series consisting of hydrogen, methyl, F, Cl, Br, I, hydroxy, (C1-C4)-alkoxy, phenyl-(C1-C4)-alkoxy- and xe2x80x94NR5aR5b, in particular from the series consisting of hydrogen, methyl, F, Br, hydroxy, methoxy, benzyloxy and xe2x80x94NHR5a.
Preferred compounds of the formula I are also those wherein three or all four of the residues R1a, R1b, R1c and R1d are hydrogen. Preferred compounds of the formula I are also those wherein the residues R1c and R1d are hydrogen.
Preferred compounds of the formula I are also those wherein the residues R1a and R1b are hydrogen or one or two of the residues R1a and R1b are different from hydrogen. Particularly preferred compounds of the formula I are those wherein one of the residues R1a and R1b is hydrogen and the other of the residues R1a and R1b is hydrogen or is different from hydrogen. Especially preferred are compounds of the formula I wherein one of the residues R1a and R1b is selected from the series consisting of hydrogen, methyl, F, Br, hydroxy, methoxy, benzyloxy and xe2x80x94NHR5a and the other of the residues R1a and R1b as well as the residues R1c and R1d are hydrogen.
Preferred compounds of the formula I are also those wherein the residue R5a is hydrogen or ((C1-C4)-alkoxy)carbonyl-, in particular hydrogen or tert-butyloxycarbonyl.
Preferred compounds of the formula I are also those wherein the residue R5b is hydrogen.
Preferred compounds of the formula I are also those wherein one of the residues R2 and R3 is xe2x80x94(CH2)pxe2x80x94COxe2x80x94R8 and the other is hydrogen, F, Cl, Br, (C1-C4)-alkyl or xe2x80x94(CH2)pxe2x80x94COxe2x80x94R8. Particularly preferred compounds of the formula I are those wherein R3 is xe2x80x94(CH2)pxe2x80x94COxe2x80x94R8, very particularly xe2x80x94COxe2x80x94R8. Particularly preferred compounds of the formula I are also those wherein R2 is hydrogen, Cl or Br. Especially preferred compounds of the formula I are those wherein R2 is hydrogen, Cl or Br and R3 is xe2x80x94(CH2)pxe2x80x94COxe2x80x94R8, in particular R3 is -CO-R8.
Preferred compounds of the formula I are also those wherein p is 0 or 1, in particular 0.
Preferred compounds of the formula I are also those wherein R8 is xe2x80x94NR9R10 or xe2x80x94OR10, in particular xe2x80x94NR9R10.
Preferred compounds of the formula I are also those wherein R9 is hydrogen.
Particularly preferred compounds of the formula I are those wherein R2 is hydrogen, Cl or Br and R3 is xe2x80x94COxe2x80x94NR9R10 or xe2x80x94COxe2x80x94OR10, especially R3 is xe2x80x94COxe2x80x94NR9R10, more especially R3 is xe2x80x94COxe2x80x94NHR10.
Preferred compounds of the formula I are also those wherein R10 is (C1-C10)-alkyl, phenyl-(C1-C4)-alkyl- or naphthyl-(C1-C4)-alkyl-, where the (C1-C10)-alkyl residue, the phenyl residue and the naphthyl residue are unsubstituted or substituted by one, two or three identical or different residues R11, and particularly the (C1-C10)-alkyl residue and the phenyl residue are substituted by one, two or three identical or different residues R11 and the naphthyl residue is unsubstituted or substituted by one, two or three identical or different residues R11, and more particularly the (C1-C10)-alkyl residue and the phenyl residue are substituted by one, two or three identical or different residues R11 and the naphthyl residue is unsubstituted.
Preferred compounds of the formula I are also those wherein R11 is R15b, (C1-C14)-alkyl, quinolinyl, isoquinolinyl or pyridyl, where quinolinyl, isoquinolinyl, and pyridyl are unsubstituted or substituted at the nitrogen atom by R14. A (C1-C4)-alkyl residue representing R11 preferably has up to 12, more preferably up to 10 carbon atoms.
Preferred compounds of the formula I are also those wherein R14 is (C1-C6)-alkyl.
Preferred compounds of the formula I are also those wherein R15b is (C1-C6)-alkyl where the alkyl residue can be substituted 1, 2, 3, 4, 5, 6 or 7 times by fluoro, or R15b is F, Cl, I, xe2x80x94(CH2)txe2x80x94N+(R16a)3Xxe2x88x92 or xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17.
Preferred compounds of the formula I are also those wherein t is 0 or 1, in particular 0, where numbers t, if present more than one time in the molecule, are independent of each other and are identical or different.
Preferred compounds of the formula I are also those wherein R16a is (C1-C6)-alkyl, (C1-C6)-alkynyl or phenyl-(C1-C6)-alkyl.
Preferred compounds of the formula I are also those wherein R17 is hydrogen.
Preferred compounds of the formula I are also those wherein A is a divalent xe2x80x94(C1-C4)-alkyl- residue, in particular a divalent xe2x80x94(C1-C4)-alkyl- residue which is saturated. Particulary preferred compounds of the formula I are those wherein A is the methylene residue xe2x80x94CH2xe2x80x94.
Preferred compounds of the formula I are also those wherein R4 is phenyl which is substituted by one residue R15c and which can additionally be substituted by one or two substituents from the series consisting of (C1-C4)-alkyl, F, Cl and Br, or R4 is pyridyl which is unsubstituted or substituted at the nitrogen atom by R14. Particularly preferred compounds of the formula I are also those wherein R4 is phenyl which is substituted by one residue R15c, especially by one residue R15c in the meta position or the para position.
Preferred compounds of the formula I are also those wherein R15c is xe2x80x94(CH2)txe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17, in particular xe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17. Moreover preferred are compounds wherein R15c is xe2x80x94(CH2)txe2x80x94C(xe2x95x90NH)xe2x80x94NH2, in particular xe2x80x94C(xe2x95x90NH)xe2x80x94NH2.
Particularly preferred compounds of the formula I are those wherein R4 is phenyl which is substituted by xe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17, especially those compounds of the formula I wherein R4 is phenyl which is substituted by xe2x80x94C(xe2x95x90NR17)xe2x80x94NHR17 in the meta position or the para position, moreover preferred those substituted in the meta position. A preferred denotation of the residue R17 present in such groups R4 is hydrogen.
Especially preferred compounds of the formula I are those wherein two or more residues are defined as indicated before for preferred compounds of the formula I, or residues can have one or some of the specific denotations of the residues given in their general definitions or in the definitions of preferred compounds before. All possible combinations of definitions given for preferred definitions and of specific denotations of residues explicitly are a subject of the present invention.
Also with respect to all preferred compounds of the formula I all their stereoisomeric forms and mixtures thereof in any ratio and their physiologically acceptable salts explicitly are a subject of the present invention, as well as are their prodrugs. Similarly, also in all preferred compounds of the formula I all residues that are present more than one time in the molecule are independent of each other and can be identical or different.
The compounds of the formula I can be prepared by utilizing procedures and techniques which per se are well known and appreciated by one of ordinary skill in the art. Starting materials or building blocks for use in the general synthetic procedures that can be applied in the preparation of the compounds of formula I are readily available to one of ordinary skill in the art. In many cases they are commercially available or have been described in the literature. Otherwise they can be prepared from readily available precursor compounds analogously to procedures described in the literature, or by procedures or analogously to procedures described in this application.
In general, compounds of the formula I can be prepared, for example in the course of a convergent synthesis, by linking two or more fragments which can be derived retrosynthetically from the formula I. More specifically, suitably substituted starting indole derivatives are employed as building blocks in the preparation of the compounds of formula I. If not commercially available such indole derivatives can be prepared according to the well-known standard procedures for the formation of the indole ring system such as, for example, the Fischer indole synthesis, the Madelung indole synthesis, the indole synthesis starting from N-chloroanilines and xcex2-ketosulfides described by Gassman et al., the Bischler indole synthesis, the Reissert indole synthesis, or the Nenitzescu indole synthesis. By choosing suitable precursor molecules, these indole syntheses allow the introduction of a variety of substituents into the various positions of the indole system which can then be chemically modified in order to finally arrive at the molecule of the formula I having the desired substituent pattern. As one of the comprehensive reviews in which numerous details and literature references on the chemistry of indoles and on synthetic procedures for their preparation can be found, volume 25, xe2x80x9cIndoles, Part Onexe2x80x9d, W. J. Houlihan (ed.), 1972, out of the series xe2x80x9cThe Chemistry of Heterocyclic Compoundsxe2x80x9d, A. Weissberger and E. C. Taylor (ed.), John Wiley and Sons, is referred to.
Examples of the many commercially available indole derivatives that are suitable as starting materials for the preparation of the compounds of formula I, are the following (the acids listed are commercially available as the free acids themselves and/or as the methyl or ethyl esters): indole-2-carboxylic acid, indole-3-carboxylic acid, indole-3-acetic acid, 3-(3-indolyl)-propionic acid, indole-2,3-dicarboxylic acid, 3-ethoxycarbonylmethyl-indole-2-carboxylic acid, 3-methyl-indole-2-carboxylic acid, 5-fluoroindole-2-carboxylic acid, 5-chloro-indole-2-carboxylic acid, 5-bromo-indole-2-carboxylic acid, 5-methoxy-indole-2-carboxylic acid, 5-hydroxy-indole-2-carboxylic acid, 5,6-dimethoxy-indole-2-carboxylic caid, 4-benzyloxy-indole-2-carboxylic acid, 5-benzyloxy-indole-2-carboxylic acid, 6-benzyloxy-5-methoxy-indole-2-carboxylic acid, 5-methyl-indole-2-carboxylic acid, 5-ethyl-indole-2-carboxylic acid, 7-methyl-indole-2-carboxylic acid, 4-methoxy-indole-2-carboxylic acid, 6-methoxy-indole-2-carboxylic acid, 4,6-dimethoxy-indole-2-carboxylic acid, 4,6-dichloro-indole-2-carboxylic acid, 5-nitro-indole-2-carboxylic acid, 5-methylsulfonyl-indole-2-carboxylic acid, 7-nitro-indole-2-carboxylic acid, 7-tert-butylcarbonylamino-indole-2-carboxylic acid, 7-(3-trifluoro-methylbenzoylamino)-indole-2-carboxylic acid, 7-(4-methoxyphenylsulfonylamino)-indole-2-carboxylic acid, 5-bromo-3-methyl-indole-2-carboxylic acid, 3-(2-carboxyethyl)-6-chloroindole-2-carboxylic acid.
If starting indole derivatives are to be synthesized this can be done, for example, according to the well known indole syntheses mentioned above. In the following they are explained briefly, however, they are standard procedures comprehensively discussed in the literature, and are well known to one skilled in the art.
The Fischer indole synthesis comprises the acid cyclization of phenylhydrazones, for example of the general formula II, 
which can be obtained by various methods and in which R30, R31 and R32 and n can have a wide variety of denotations. Besides hydrogen and alkyl, R31 and R32 can especially denote ester groups or methyl or ethyl groups carrying an ester group as substituent thus allowing the introduction into the indole molecule of the (CH2)pxe2x80x94CO moiety occurring in the groups R2 and/or R3 in the compounds of the formula I. As examples of the many literature references describing the synthesis of indole derivatives according to the Fischer synthesis, besides the above-mentioned book edited by Houlihan, the following articles are mentioned: F. G. Salituro et al., J. Med. Chem. 33 (1990), 2944; N. M. Gray et al., J. Med. Chem. 34 (1991); 1283; J. Sh. Chikvaidze et al., Khim. Geterotsikl. Soedin. (1991), 1508; S. P. Hiremath et al., Indian J. Chem. 19 (1980), 770; J. Bornstein, J. Amer. Chem. Soc. 79 (1957), 1745.
The Reissert indole synthesis comprises the reductive cyclization of o-nitrophenylpyruvic acids or esters therof, for example of the general formula 
in which the groups R30 can have a wide variety of denotations and can be present in all positions of the benzene ring. The Reissert indole synthesis leads to derivatives of indole-2-carboxylic acids. The pyruvic acid derivatives of the formula III can be obtained by condensation of oxalic acid esters with substituted o-nitrotoluenes. As literature references, besides the above-mentioned book edited by Houlihan and the literature articles mentioned therein, for example the articles by H. G. Lindwall and G. J. Mantell, J. Org. Chem. 18 (1953), 345 or by H. Burton and J. L. Stoves, J. Chem. Soc. (1937), 1726 are mentioned.
According to the Bischler indole synthesis xcex1-anilinoketones, for example of the general formula IV, 
can be cyclized to indole derivatives.
The Nenitzescu indole synthesis provides a valuable route to indole-3-carboxylic acid derivatives carrying a hydroxy group in the 5-position. It comprises the reaction of a para-benzoquinone with a xcex2-aminocrotonate, for example of the compounds of the formulae V and VI. 
A further route to specifically substituted indole derivatives proceeds via 2,3-dihydroindoles (indolines) which can be easily obtained by reduction of indoles, for example by hydrogenation, or by cyclization of suitable phenylethylamine derivatives. Indolines can undergo a variety of electrophilic aromatic substitution reaction allowing the introduction of various substituents into the benzene nucleus which cannot directly be introduced by such reactions into the benzene nucleus of the indole molecule. The indolines can then be dehydrogenated to the corresponding indoles, for example with reagents like chloranil or palladium together with a hydrogen acceptor. Again, details on these syntheses can be found in the above-mentioned book edited by Houlihan.
Depending on the substituents in the starting materials, in certain indole syntheses mixtures of positional isomers may be obtained which, however, can be separated by modern separation techniques like, for example, preparative HPLC.
Further, in order to obtain the desired substituents in the benzene nucleus and in the heterocyclic nucleus of the indole ring system in the formula I, the functional groups introduced into the ring system during the indole synthesis can be chemically modified. For example, indoles carrying a hydrogen atom in the 2-position or the 3-position can also be obtained by saponification and subsequent decarboxylation of indoles carrying an ester group in the respective position. Carboxylic acid groups and acetic acid groups in the 2-position and the 3-position can be converted into their homologues by usual reactions for chain elongation of carboxylic acids. Halogen atoms can be introduced into the 2-position or the 3-position, for example by reacting the respective indolinone with a halogenating agent such as phosphorus pentachloride analogously to the method described by J. C. Powers, J. Org. Chem. 31 (1966), 2627. The starting indolinones for such a synthesis can be obtained from 2-aminophenyl acetic acids. Starting indole derivatives for the preparation of compounds of the formula I carrying a halogen substituent in the 3-position can also be obtained according to procedures described in the literature like the following. Chlorination of 1H-indole-2-carboxylic acid ethyl ester in the 3-position by reaction with sulfuryl chloride in benzene yields 3-chloro-1H-indole-2-carboxylic acid ethyl ester (Chem. Abstr. 1962, 3441i-3442b). 3-Bromo-1-(3-cyano-benzyl)-1H-indole-2-carboxylic acid ethyl ester can be synthesized analogously to J. Het. Chem 33 (1996), 1627 by reaction of 1-(3-cyano-benzyl)-1H-indole-2-carboxylic acid ethyl ester with pyridinium bromide perbromide in pyridine.
Especially the groups present in the benzene nucleus of the indole ring system can be modified by a variety of reactions and thus the desired residues R1a, R1b, R1c and R1d be obtained. For example, nitro groups can be reduced to amino group with various reducing agents, such as sulfides, dithionites, complex hydrides or by catalytic hydrogenation. A reduction of a nitro group may also be carried out at a later stage of the synthesis of a compound of the formula I, and a reduction of a nitro group to an amino group may also occur simultaneously with a reaction performed on another functional group, for example when reacting a group like a cyano group with hydrogen sulfide or when hydrogenating a group. In order to introduce the residues R5a, R5b and R6axe2x80x94SO2, amino groups can then be modified according to standard procedures for alkylation, for example by reaction with (substituted) alkyl halogenides or by reductive amination of carbonyl compounds, according to standard procedures for acylation, for example by reaction with activated carboxylic acid derivates such as acid chlorides, anhydrides, activated esters or others or by reaction with carboxylic acids in the presence of an activating agent, or according to standard procedures for sulfonylation, for example by reaction with sulfonyl chlorides.
Ester groups present in the benzene nucleus can be hydrolyzed to the corresponding carboxylic acids which after activation can then be reacted with amines or alcohols under standard conditions. Ether groups present at the benzene nucleus, for example benzyloxy groups or other easily cleavable ether groups, can be cleaved to give hydroxy groups which then can be reacted with a variety of agents, for example etherification agents or activating agents allowing replacement of the hydroxy group by other groups. Sulfur-containing groups can be reacted accordingly.
The before-mentioned reactions for the conversion of functional groups are in general extensively described in textbooks of organic chemistry and in treatises like Houben-Weyl, xe2x80x9cMethoden der Organischen Chemiexe2x80x9d (Methods of Organic Chemistry), Georg Thieme Verlag, Stuttgart, Germany, or xe2x80x9cOrganic Reactionsxe2x80x9d, John Wiley and Sons, New York, in which details on the reactions and primary source literature can be found. Due to the fact that in the present case the functional groups are attached to an indole ring it may in certain cases become necessary to specifically adapt reaction conditions or to choose specific reagents from a variety of reagents that can in principle be employed into a conversion reaction, or otherwise to take specific measures for achieving a desired conversion, for example to use protection group techniques. However, finding out suitable reaction variants and reaction conditions in such cases does not cause any problems for one skilled in the art.
The structural elements present in the residues in the 1-position of the indole ring in the compounds of the formula I and in the COR8 group present in the 2-position and/or in the 3-position of the indole ring can be introduced into the starting indole derivative obtainable as outlined above by consecutive reaction steps like those outlines below using procedures which per se are well known to one skilled in the art.
The residues R8 that can be present in R2 and/or R3 can be introduced, for example, by condensing a corresponding carboxylic acid of the formula VII or a derivative thereof with a compound or with compounds of the formula HR8xe2x80x2, i.e. with an amine of the formula HNR9xe2x80x2R10xe2x80x2 and/or with an alcohol of the formula HOR10xe2x80x2 and/or with a mercaptan of the formula HSxe2x80x94(C1-C4)-alkyl to give a compound of the formula VIII. The compound of the formula VIII thus obtained can already contain the desired final groups, i.e. the groups R8 and R40 can be the groups R8 and R4xe2x80x94Axe2x80x94 defined as for the formula I, or optionally in the compound of the formula VIII thus obtained subsequently the residue or the residues R8xe2x80x2 and the residue R40 are converted into the residues R8 and R4xe2x80x94Axe2x80x94, respectively, to give the desired compound of the formula I. 
Thus, the residues R8xe2x80x2 and the residues R9xe2x80x2 and R10xe2x80x2 contained therein can have the denotations of R8, R9 and R10, respectively, given above or in addition in the residues R8xe2x80x2, R9xe2x80x2 and R1xe2x80x2 functional groups can also be present in the form of groups that can subsequently be transformed into the final groups R8, R9 and R10, i.e. functional groups can be present in the form of precursor groups or of derivatives, for example in protected form. Examples of precursor groups are cyano groups which may in a later step be transformed into carboxylic acid derivatives or by reduction into aminomethyl groups, or nitro groups which may be transformed by reduction like catalytic hydrogenation into amino groups.
The residue R40 in the compounds of the formulae VII and VIII can denote the group xe2x80x94Axe2x80x94R4 as defined above which finally is to be present in the desired target molecule of the formula I, or it can denote a group which can subsequently be transformed into the group xe2x80x94Axe2x80x94R4, for example a precursor group or a derivative of the group xe2x80x94Axe2x80x94R4 in which functional groups are present in protected form, or R40 can denote a hydrogen atom or a protective group for the nitrogen atom of the indole ring. Similarly, the residues R1a, R1b, R1c and R1d and the numbers p in the formulae VII and VIII are defined as above, however, for the synthesis of the compounds of the formula I these residues, too, can in principle be present at the stage of the condensation of a compound of the formula VII with a compound of the formula HR8xe2x80x2 giving a compound of the formula VIII in the form of precursor groups or in protected form.
The residues R41 in the compounds of the formula VII which can be identical or different, can be, for example, hydroxy or (C1-C4)-alkoxy, i.e., the groups COR41 present in the compounds of the formula VII can be, for example, the free carboxylic acids or esters thereof like alkyl esters as can be the groups COR8 in the compounds of the formula I. The groups COR41 can also be any other activated derivative of a carboxylic acid which allows amide formation, ester formation or thioester formation with a compound of the formula HR8xe2x80x2. The group COR41 can be, for example, an acid chloride, an activated ester like a substituted phenyl ester, an azolide like an imidazolide, an azide or a mixed anhydride, for example a mixed anhydride with a carbonic acid ester or with a sulfonic acid, which derivatives can all be prepared from the carboxylic acid by standard procedures and can be reacted with an amine, an alcohol or a mercaptan of the formula HR8xe2x80x2 under standard conditions. A carboxylic acid group COOH representing COR41 in a compound of the formula VII can be obtained, for example, from an ester group introduced into the indole system during an indole synthesis by standard hydrolysis procedures.
Compounds of the formula I in which a group COR8 is an ester group can also be prepared from compounds of the formula VII in which COR41 is a carboxylic acid group by common esterification reactions like, for example, reacting the acid with an alcohol under acid catalysis, or alkylation of a salt of the carboxylic acid with an electrophile like an alkyl halogenide, or by transesterification from another ester. Compounds of the formula I in which a group COR8 is an amide group can be prepared from amines and compounds of the formula VII in which COR41 is a carboxylic acid group or an ester thereof by common amination reactions. Especially for the preparation of amides the compounds of the formula VII in which COR41 is a carboxylic acid group can be condensed under standard conditions with compounds of the formula HR8xe2x80x2 which are amines by means of common coupling reagents used in peptide synthesis. Such coupling reagents are, for example, carbodiimides like dicyclohexylcarbodiimide (DCC) or diisopropylcarbodiimide, carbonyidiazoles like carbonyidiimidazole and similar reagents, propylphosphonic anhydride, O-((cyano-(ethoxycarbonyl)-methylene)amino)-N,N,Nxe2x80x2,Nxe2x80x2-tetramethyluronium tetrafluoroborate (TOTU) and many others.
If in the compounds of the formula VII two identical groups COR41, for example two COOH groups, are present and only one of them is to be condensed with the compound HR8xe2x80x2, or if the two groups are to be condensed with two different compounds HR8xe2x80x2, the condensation reaction has to be suitably adapted. Such an adaption will not constitute a problem for one skilled in the art. As a reference discussing such reactions, for example, Y. Miki, H. Hachiken and I. Yoshikawa, Heterocycles 45 (1997), 1143 may be mentioned. The desired result can, for example, be achieved by using reagents and/or reaction conditions which allow a selective reaction of the two groups, or by applying a protective group strategy. In the latter case one of the groups is first selectively protected, for example by transformation into an appropriate ester or another protected form of a carboxylic acid, then the other group is condensed with the compound of the formula HR8xe2x80x2, and then the first group is deprotected and, if desired, is reacted with a second compound of the formula HR8xe2x80x2. Different groups COR41, for example one ester group and one free carboxylic acid group may, however, also be initially present in the starting indole derivative of the formula VII employed into the condensation reaction.
If the residue R4xe2x80x94Axe2x80x94 present in an indole of the formula I or the residue R40 present in an indole of the formula VII, or a residue in which functional groups within the residue R4xe2x80x94Axe2x80x94 or R40 are present in protected form or in the form of a precursor group, have not already been introduced during a preceding step, for example during a synthesis of the indole nucleus, these residues can, for example, be introduced into the 1-position of the indole system by conventional literature procedures well known to one skilled in the art for N-alkylation, N-arylation, N-acylation or N-sulfonylation of ring nitrogen atoms of heterocycles. The starting indole derivative that is to be employed in such a reaction carries a hydrogen atom in the 1-position. N-Alkylation of a ring nitrogen atom can, for example, be performed under standard conditions, preferably in the presence of a base, using an alkylating compound of the formula R4xe2x80x94Axe2x80x94LG or of the formula R40xe2x80x94LG, wherein the atom in the group A or in the group R40 bonded to the group LG in this case is an aliphatic carbon atom of an alkyl moiety and LG is a leaving group, for example halogen like chlorine, bromine or iodine, or a sulfonyloxy group like tosyloxy, mesyloxy or trifluormethylsulfonyloxy. LG may, for example, also be a hydroxy group which, in order to achieve the alkylation reaction, is activated by a conventional activating agent. For the preparation of compounds in which A is a direct linkage and an aromatic group is directly bonded to the 1-position of the indole system, conventional arylation procedures can be used. For example aryl fluorides like nitroaryl fluorides or cyanoaryl fluorides can be employed as arylating agents which advantageously allow the subsequent formation of an amino group. Such processes are described, for example, in Tetrahedron Lett. 37 (1996), 299; Tetrahedron Lett. 36 (1995), 8387; Synth. Commun. 25 (1995), 2165; J. Med. Chem. 28 (1985), 66.
A guanidino function present in a compound of the formula I can be introduced by conversion of an amino function which, for example, may be obtained by reduction of a nitro function or a cyano function, using the following reagents:
1. O-Methylisourea (S. Weiss and H. Krommer, Chemiker-Zeitung 98 (1974), 617-618)
2. S-Methylisothiourea (R. F. Borne, M. L. Forrester and I. W. Waters, J. Med. Chem. 20 (1977), 771-776)
3. Nitro-S-methylisothiourea (L. S. Hafner and R. E. Evans, J. Org. Chem. 24 (1959), 1157)
4. Formamidinosulfonic acid (K. Kim, Y.-T. Lin and H. S. Mosher, Tetra. Lett. 29 (1988), 3183-3186)
5. 3,5-Dimethyl-1-pyrazolylformamidinium nitrate (F. L. Scott, D. G. O""Donovan and J. Reilly, J. Amer. Chem. Soc. 75 (1953), 4053-4054)
6. N,Nxe2x80x2-Di-tert-butyloxycarbonyl-S-methylisothiourea (R. J. Bergeron and J. S. McManis, J. Org. Chem. 52 (1987), 1700-1703)
7. N-Alkoxycarbonyl-, N,Nxe2x80x2-dialkoxycarbonyl-, N-alkylcarbonyl- and N,Nxe2x80x2-dialkylcarbonyl-S-methylisothiourea (H. Wollweber, H. Kxc3x6lling, E. Niemers, A. Widdig, P. Andrews, H.-P. Schulz and H. Thomas, Arzneim. Forsch./Drug Res. 34 (1984), 531-542).
Amidines can be prepared from the corresponding cyano compounds by addition of alcohols, for example methanol or ethanol, in an acidic anhydrous medium, for example dioxane, methanol or ethanol, and subsequent aminolysis, for example treatment with ammonia in alcohols such as, for example, isopropanol, methanol or ethanol (G. Wagner, P. Richter and Ch. Garbe, Pharmazie 29 (1974), 12-55). Further methods of preparing amidines are the addition of hydrogen sulfide to a cyano group, followed by alkylation, for example by methylation with an agent like methyl iodide, of the resulting thioamide and subsequent reaction with ammonia (GDR Patent No. 235 866), or the addition of hydroxylamine which may be obtained from a hydroxylammonium salt with a base, to the cyano group followed by conversion of the amidoxime to the amidine, for example by catalytic hydrogenation (see, for example, R. P. Mull et al., J. Med. Pharm. Chem. 5 (1962), 651; B. J. Broughton et al., J. Med. Chem. 18 (1975), 1117).
Compounds of the formula I in which a group ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94 bonded to a nitrogen atom is present can be prepared from a precursor compound containing said nitrogen atom as an NH group, for example, by the following methods. The precursor compound containing the NH group is reacted with a mono- or bis-benzyloxycarbonyl (Z) protected alkylamidine of the formulae ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94NHxe2x80x94Z or ((C1-C6)-alkyl)-C(xe2x95x90NZ)xe2x80x94NHxe2x80x94Z of which the bis-protected reagent is more reactive than the mono-protected one (Y. Sugimura et al., Heterocycles 24 (1986), 1331-1345; J. Eustache and A Grob, Tetrahedron Lett. 36 (1995), 2045-2046). In another method, the precursor compound containing the NH group is reacted with an imino ether, for example, of the formula ((C1-C6)-alkyl)-C(xe2x95x90NH)xe2x80x94Oxe2x80x94((C1-C4)-alkyl) which in turn is available under standard conditions from a nitrile of the formula ((C1-C6)-alkyl)-CN by addition of an alcohol in the presence of an acid. If two or more NH groups are present in the compound to be reacted with the imino ether or the Z-protected alkylamidine protection group strategies can be used to achieve the desired result, as is well known to one skilled in the art.
An imino ether which can be regarded as an activated nitrile, is also a versatile intermediate in case it is prepared from a cyano group that is present in a compound which already contains the indole system and which has been obtained as an intermediate during the synthesis of a compound of the formula I. For example, a cyano group that is present in the residue R40 in a compound of the formulae VII or VII or in another residue can be reacted according to standard procedures to give an imino ether. Such an imino ether can be reacted, for example, with hydroxylamine to give an amidoxime group, or it can be reacted with 1,2-diaminoethane to give an imidazoline group, i.e. a 4,5-dihydro-1H-imidazol-2-yl substituent standing in place of the former cyano group. Again, in such reactions as in all reactions employed in the synthesis of the compounds of the formula I, depending on the individual case it may be favorable in order to avoid undesired reactions or secondary reactions to apply protection group techniques and to temporarily block groups like, for example, amino groups or carboxylic acid groups by protective groups suited to the specific synthesis problem.
Compounds of the formula I in which an amine oxide moiety or a pyridine N-oxide, quinoline N-oxide or isoquinoline N-oxide moiety is present can be obtained by oxidation of the amines or of the nitrogen heterocycles according to standard procedures as are described, for example, in J. March, Advanced Organic Chemistry, 3. ed., p. 1088.
The compounds of the formula I can also be prepared, for example, by synthesizing the compounds stepwise on a solid phase according to customary methods of solid phase chemistry which are well known to one skilled in the art and which are illustrated by the examples below.
Compounds of the formula la in which R2 and R3 in the formula I together form a group of the formula xe2x80x94CH2xe2x80x94CH2xe2x80x94N(xe2x80x94COxe2x80x94R20)xe2x80x94CH2xe2x80x94 can be prepared according to the above procedures starting from suitably substituted compounds of the formula IX which are commercially available or which can be prepared according to or analogously to syntheses described in the literature. In the formulae Ia and IX the residues have the meanings defined above. 
As is demonstrated in the pharmacological tests described below, the compounds of the formula I inhibit factor Xa activity. They can therefore advantageously be used as pharmaceuticals, especially when it is desired to reduce factor Xa activity or to produce effects that can be achieved by inhibiting factor Xa activity in a system, such as influencing coagulation or inhibiting blood clotting. Thus, the present invention also relates to the compounds of the formula I for use as pharmaceuticals as well as to the compounds of the formula I for use in the production of medicaments, especially of medicaments for treatment or prophylaxis of the conditions and diseases mentioned below and above. Further, the present invention provides a method of specifically inhibiting factor Xa activity by contacting factor Xa with a compound of the formula I, wherein a compound of the invention inhibits factor Xa catalytic activity either directly, within the prothrombinase complex or as a soluble subunit, or indirectly, by inhibiting the assembly of factor Xa into the prothrombinase complex. A preferred embodiment of the invention comprises such compounds of the formula I which can inhibit factor Xa activity with a Kixe2x89xa6100 xcexcM and, more preferably, with a Kixe2x89xa62 xcexcM as determined in the factor Xa assay described below.
Inhibition of factor Xa activity or the production of effects achieved by such an inhibition can take place, for example, in vivo, i.e. in an individual. As used herein, the term xe2x80x9cindividualxe2x80x9d means a vertebrate, including a mammal such as, for example a mouse, a rat, a rabbit, a dog, a pig and especially a human, in which factor Xa is involved in the coagulation cascade. It can also take place outside the body of an individual, for example, in an extracorporeal circulation or in the treatment of blood samples from an individual, and generally in vitro. In vitro uses of the compounds of the formula I are, for example, the use as a biochemical tool or reagent in scientific or analytical investigations or the use in in vitro diagnoses. Further, a compound of the formula I can advantageously be used as an anticoagulant which can be contacted with a blood sample to prevent coagulation. For example, an effective amount of a compound of the formula I can be contacted with a freshly drawn blood sample to prevent coagulation of the blood sample.
As used herein, the term xe2x80x9ceffective amountxe2x80x9d when used in this connection means an amount of a compound of the formula I that inhibits factor Xa activity to the desired extent. The skilled artisan would recognize that an effective amount of a compound of the invention can be determined using the methods disclosed herein or otherwise known in the art.
In view of the disclosed utility of the compounds of the formula I, the skilled artisan also would recognize that an agent such as heparin can be replaced with a compound of the invention. Such a use of a compound of the formula I can result, for example, in a cost saving as compared to other anticoagulants, or in less side effects.
In a further embodiment, the present invention provides a method of inhibiting factor Xa in a patient in need thereof, comprising administering to said patient an effective factor Xa inhibitory amount of a compound of the formula I. As used herein, the term xe2x80x9cpatientxe2x80x9d refers especially to a warm-blooded animal including a mammal and particularly a human. A patient is in need of treatment to inhibit factor Xa when the patient is suffering from a disease state that can be beneficially influenced by inhibiting factor Xa activity or that is expected by the clinician to be beneficially influenced by inhibiting factor Xa acitivity. The identification of those patients who are in need of treatment to inhibit factor Xa is well within the ability and knowledge of one skilled in the art. A clinician skilled in the art can readily identify, for example by the use of clinical tests, physical examination and medical/family history, those patients who are in need of such a treatment.
Since a compound of the formula I can inhibit factor Xa activity, such a compound can be used for reducing or inhibiting blood clotting in an individual. Thus, the present invention further provides a method of reducing or inhibiting the formation of blood clots in an individual, especially in a patient in need thereof, by administering a therapeutically effective amount of a compound of the formula I.
A xe2x80x9ctherapeutically effective amountxe2x80x9d relating to the production in an individual of an effect like inhibition or reduction of blood clotting, or an xe2x80x9ceffective factor Xa inhibitory amountxe2x80x9d of a compound of the formula I means the amount or the dose of a compound of the formula I that has to be administered to an individual in order to achieve or to maintain the desired effect, or to inhibit factor Xa activity in the individual to the desired extent. Such an effective amount or dose to be administered has to be adjusted to the individual circumstances in each case. It can be readily determined by the use of conventional techniques using the methods described herein or otherwise known in the art, and by observing results obtained under analogous circumstances. In determining the effective dose, a number of factors are considered including, but not limited to the species of the patient; its size, age, and general health; the specific disease involved; the degree or the involvement or the severity of the disease; the response of the individual patient; the particular compound administered; the mode of administration; the bioavailability characteristics of the pharmaceutical preparation administered; the dose regimen selected; and the use of concomitant medication. An appropriate dosage can be established using clinical approaches well known in the medical art.
In general, in view of the above factors it is evident that the effective factor Xa inhibitory amount or the therapeutically effective amount of a compound of the formula I will vary and can be varied within wide limits. Usually, an effective amount of a compound of the formula I will vary from about 0.01 milligram per kilogram of body weight per day (mg/kg per day) to about 20 mg/kg per day. A daily dose of from about 0.1 mg/kg to about 10 mg/kg usually is preferred. These data refer to an adult human of about 75 kg of body weight. However, depending on the individual circumstances it may be necessary to deviate upward or downward from the doses given. In particular when administering relatively large quantities, it can be favorable to subdivide the daily dose into several, for example 2, 3 or 4 subdose administrations.
A compound of the formula I can be administered to an individual for the treatment of a variety of clinical conditions including, for example, the treatment and prophylaxis of cardiovascular disorders or complications associated, for example, with infection or surgery. Examples of cardiovascular disorders include restenosis, for example restenosis following angioplasty, reocclusion prophylaxis including reocclusion prophylaxis following lysis or dilatation (PTCA), conditions after coronary bypass operations, arterial, venous and microcirculatory disease states, cardiac infarction, angina pectoris including unstable angina pectoris, thromboembolic diseases, thromboses, embolism, adult respiratory distress syndrome, multi-organ failure, stroke and disseminated intravascular coagulation clotting disorder. Examples of related complications associated with surgery include, for example, deep vein and proximal vein thrombosis, which can occur following surgery. In general, a compound of the invention is useful as a medicament for reducing or inhibiting or preventing unwanted coagulation or blood clotting or thrombus formation in an individual.
The compounds of the formula I, their physiologically acceptable salts and other suitable derivatives thereof like prodrugs can be administered as medicaments or pharmaceuticals in the above-mentioned methods of treatment or prophylaxis on their own, in mixtures with each other or in the form of pharmaceutical compositions which comprise, as the active ingredient, an effective amount of at least one compound of the formula I and/or of a physiologically acceptable salt and/or another suitable derivative thereof in admixture or otherwise in association with a pharmaceutically acceptable carrier.
In effecting treatment of a patient, compounds of the formula I or pharmaceutical compositions comprising them can be administered in any form or mode which makes the compounds of the formula I bioavailable in effective amounts, including oral and parenteral routes. For example, they can be administered orally, subcutaneously, intramuscularly, intravenously, transdermally, intranasally, rectally, and the like. Oral administration is generally preferred but depending on the specific case other modes of administration can also be favorable, for example in an acute stage of a disease intravenous administration by means of injection or infusion. One skilled in the art can readily select the proper form and mode of administration depending upon the disease state to be treated, the stage of the disease, and other relevant circumstances.
Pharmaceutical compositions or medicaments comprising a compound of the formula I and/or a physiologically acceptable salt and/or another suitable derivative thereof can be made by combining by standard procedures the compounds of the formula I and/or their physiologically acceptable salts and/or other suitable derivatives thereof with one or more pharmaceutically acceptable carrier substances and/or auxiliary substances the proportion and nature of which are determined by the chosen route of administration and standard pharmaceutical practice. The pharmaceutical compositions or medicaments are prepared in a manner well known in the pharmaceutical art. The pharmaceutical compositions will, in general, contain an effective amount of one or more compounds of the formula I and/or their physiologically acceptable salt and/or other suitable derivatives thereof together with a suitable amount of a carrier so as to comprise the proper dosage for administration to an individual. The pharmaceutical compositions may be adapted for oral or parenteral use and may be administered to the patient in the form of, for example, tablets, capsules, suppositories, solutions, suspensions, ointments, tinctures, nasal sprays, aerosol mixtures, implants, rods, microcapsules or the like. Thus, together with the claimed compounds of the formula I the present invention provides useful pharmaceutical compositions or medicaments for inhibiting factor Xa activity, for inhibiting blood clotting and for the treatment and prophylaxis of the above-mentioned diseases in an individual. The present invention further encompasses a process for the preparation of pharmaceutical compositions or medicaments which comprise at least one compound of the formula I and/or a physiologically acceptable salt and/or another suitable derivative thereof, as well as it encompasses the use of the compounds of the formula I and/or physiologically acceptable salts and/or other suitable derivatives thereof for the preparation of medicaments, especially of medicaments for the treatment or prophylaxis of the above-mentioned diseases.
Pharmaceutically acceptable carrier and auxiliary substances are referred to as substances or compositions that are non-toxic to an individual or have acceptable toxicity as determined by the appropriate regulatory agency. The carrier substance or excipient may be a solid, semi-solid, or liquid material which can serve as a vehicle or medium for the active ingredient. As used herein, the term xe2x80x9cpharmaceutically acceptable carrierxe2x80x9d encompasses any of the standard pharmaceutical carriers such as liquid carriers, for example water, saline, phosphate buffered saline, an emulsion such as an oil/water or water/oil emulsion, or solid or semi-solid carriers such as, for example, lactose, corn starch, fats, waxes, etc. Suitable pharmaceutical carriers and their formulations are well known in the art and are described, for example, by Martin in Remington""s Pharmaceutical Sciences, 15th Ed., Mack Publishing Co., Easton 1975, which is incorporated herein by reference also with respect to other aspects of the ingredients and of the preparation of pharmaceutical compositions.
Examples of auxiliary substances are fillers, disintegrants, binders, glidants, wetting agents, stabilizers, emulsifiers, preservatives, sweeteners, dyes, flavorants, aromatizing agents, thickeners, diluents, buffering substances, solubilizing agents, agents for achieving a slow-release effect, salts for altering the osmotic pressure, coating agents, antioxidants, etc.
For the purpose of oral administration, the compounds of the formula I and/or of their physiologically acceptable salts and/or other suitable derivatives thereof may be incorporated with excipients or inert diluents or edible carriers and used in the form of, for example, tablets, film tablets, coated tablets, pills, troches, capsules, granules, solutions, suspensions, emulsions, elixirs, syrups, wafers, chewing gums and the like, or they may be enclosed in gelatin capsule. The pharmaceutical compositions for oral administration may be varied depending upon the particular form. Usually such pharmaceutical compositions contain at least 1% of the active ingredient of the formula I and/or of a physiologically acceptable salt and/or another suitable derivative thereof and may conveniently contain up to about 90% of the weight of the unit. Preferably the content of the compounds of the formula I and/or their physiologically acceptable salts and/or other suitable derivatives is from about 4% to about 70% by weight. Preferably the amount of the active ingredient present in the compositions is such that a unit dosage form suitable for administration will be obtained.
The tablets, pills, capsules, troches and the like may also contain, for example, one or more of the following carrier and auxiliary substances: binders, such as microcrystalline cellulose, gum tragacanth or gelatin; excipients, such as starch or lactose, disintegrating agents such as alginic acid, Primogel, corn starch and the like; lubricants, such as magnesium stearate or Sterotex; glidants, such as colloidal silicon dioxide. Further, sweetening agents such as sucrose or saccharin may be added or flavoring agents such as peppermint, methyl salicylate or orange flavoring. When the dosage unit form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier such as polyethylene glycol or a fatty oil. Other dosage unit forms may contain various other materials which modify the physical form of the dosage unit, for example, as coatings. Thus, tablets or pills may be coated with sugar, shellac, or other enteric coating agents. A syrup may contain, in addition to the active ingredient, for example sucrose as a sweetening agent and certain preservatives, dyes and colorings and flavors.
For the purpose of, for example, parenteral administration the compounds of the formula I and/or physiologically acceptable salts thereof and/or other suitable derivatives thereof may be incorporated into a solution or a suspension. The solutions or suspensions may, for example, also include one or more of the following carrier and auxiliary substances: sterile diluents such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine, propylene glycol or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl paraben; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylene diaminetetraacetic acid; buffers such as acetates, citrates or phosphates; agents for the adjustment of toxicity such as sodium chloride or dextrose. The content of the compounds of the formula I and/or of their physiologically acceptable salt and/or other suitable derivatives thereof in the preparations for parenteral adminstration may be varied. Usually they contain at least 0.1% by weight of the compound of the formula I and/or of a physiologically acceptable salt and/or another suitable derivative thereof and up to 90% by weight. Preferably the content of the compound of the formula I and/or the physiologically acceptable salts thereof and/or other suitable derivatives thereof is from about 0.1% to 50%. The parenteral preparations can be enclosed, for example, in ampules, disposable syringes, multiple dose vials made of glass or plastic, or infusion bottles. Suitable excipients for microcapsuies, implants and rods are, for example, mixed polymers of glycolic acid and lactic acid.
Generally, the amount of the compounds of the formula I and/or physiologically acceptable salts thereof and/or other suitable derivatives thereof that is present in a pharmaceutical composition is from about 0.5 mg to about 1 g, preferably from about 1 mg to about 500 mg. Besides one or more compounds of the formula I and/or one or more physiologically acceptable salts thereof and/or one or more other suitable derivatives thereof as active compounds the pharmaceutical compositions according to present invention may also contain one or more other pharmacologically active compounds. Any materials used in preparing the various pharmaceutical compositions should be pharmaceutically pure and non-toxic in the amounts used.
In another, more general embodiment the present invention provides compositions comprising at least one compound of the formula I and/or a salt thereof and/or another suitable derivative thereof in admixture or otherwise in association with one or more inert carriers. These compositions are useful, for example, as assay standards, as convenient means of making bulk shipments, as pharmaceutical compositions or as starting materials for the production of pharmaceutical compositions. The amount of a compound of the formula I in such a composition will generally vary from about 0.001% to about 90% by weight. Inert carriers can be any material which does not degrade or otherwise covalently react with a compound of the formula I. Examples of suitable inert carriers are water; aqueous buffers, such as, for example, those which are generally useful in High Performance Liquid Chromatography (HPLC) analysis; organic solvents, such as acetonitrile, ethyl acetate, hexane and the like; and pharmaceutically acceptable carrier and/or auxiliary substances.
The compounds of the formula I can also be used as starting materials or chemical intermediates in the preparation of other compounds, especially in the preparation of other pharmacologically active compounds. Examples for such conversions of compounds of the invention into other compounds of the invention are discussed above and are given in detail below. For this use, besides the compounds of the formula I and their physiologically acceptable salts also other salts of the compounds of the formula I can be useful which are not suitable or less suitable for use as pharmaceuticals. Thus, the present invention also relates to compounds of the formula I and their salts in general as chemical intermediates, especially as intermediates in the preparation of pharmacologically active compounds. A subject of the invention also are intermediates which are used in the syntheses of the compounds of the formula I described above and below, and their use as chemical intermediates, especially as intermediates in the preparation of pharmacologically active compounds.
The following tests can serve to investigate the pharmacological activity and to illustrate the utility of the compounds of the present invention as factor Xa inhibitors.
Test 1: In Vitro Inhibition of Selected Purified Coagulation Enzymes and Other Serine Proteases
The ability of a compound of the formula I to inhibit factor Xa, thrombin, plasmin, elastase and trypsin may be assessed by determining the concentration of the compound of the formula I that inhibits enzyme activity by 50% (IC50). Purified enzymes are used in chromogenic assays. To determine the inhibition constant Ki, the IC50 value is corrected for competition with substrate using the formula
Ki""IC50xc3x97(1/{1+((substrate concentration)/substrate Km)})
wherein Km is the Michaelis-Menten constant (Chen and Prusoff, Biochem. Pharmacol. 22 (1973), 3099-3018 which is incorporated herein by reference).
a. Factor Xa Assay
TBS-PEG buffer (50 mM Tris-Cl, pH 7.8, 200 mM NaCl, 0.05% (w/v) PEG-8000, 0.02% (w/v) NaN3) is used for this assay. The IC50 is determined by combining in appropriate wells of a Costar half-area microtiter plate 25 xcexcl human factor Xa (Enzyme Research Laboratories, Inc.; South Bend, Ind.) in TBS-PEG; 40 xcexcl 10% (v/v) DMSO in TBS-PEG (uninhibited control) or various concentrations of the compound to be tested diluted in 10% (v/v) DMSO in TBS-PEG; and substrate S-2765 (N(xcex1)-benzyloxycarbonyl-D-Arg-Giy-L-Arg-p-nitroanilide; Kabi Pharmacia, Inc.; Franklin Ohio) in TBS-PEG.
The assay is performed by pre-incubating the compound of formula I plus enzyme for 10 min. Then the assay is initiated by adding substrate to obtain a final volume of 100 xcexcl. The initial velocity of chromogenic substrate hydrolysis is measured by the change in absorbance at 405 nm using a Bio-tek Instruments kinetic plate reader (Ceres UV900HDi) at 25xc2x0 C. during the linear portion of the time course (usually 1.5 min after addition of substrate). The concentration of inhibitor that causes a 50% decrease in the rate of substrate hydrolysis is predicted by linear regression after plotting the relative rates of hydrolysis (compared to the uninhibited control) versus the log of the concentration of the compound of formula I. The enzyme concentration is 0.5 nM and substrate concentration is 140 xcexcM.
b. Thrombin Assay
TBS-PEG buffer is used for this assay. The IC50 is determined as above for the factor Xa assay, except that the substrate is S-2366 (L-PyroGlu-L-Pro-L-Arg-p-nitroanilide; Kabi) and the enzyme is human thrombin (Enzyme Research Laboratories, Inc.; South Bend Ind.). The enzyme concentration is 175 xcexcM.
c. Plasmin Assay
TBS-PEG buffer is used for this assay. The IC50 is determined as described above for the factor Xa assay, except that the substrate is S-2251 (D-Val-L-Leu-L-Lys-p-nitroanilide; Kabi) and the enzyme is human plasmin (Kabi). The enzyme concentration is 5 nM and the substrate concentration is 300 xcexcM.
d. Trypsin Assay
TBS-PEG buffer containing 10 mM CaCl2 is used for this assay. The IC50 is determined as described above in the factor Xa assay, except that the substrate is BAPNA (benzoyl-L-Arg-p-nitroanilide; Sigma Chemical Co.; St. Louis Mo.) and the enzyme is bovine pancreatic trypsin (Type XIII, TPCK treated; Sigma). The enzyme concentration is 50 nM and the substrate concentration is 300 xcexcM.
e. Elastase Assay
Tris-Cl buffer (pH 7.4, 300 mM NaCl, 2% (v/v) N-methyl-pyrrolidone, 0.01% (w/v) NaN3) is used for this assay. The IC50 is determined as described above for the assay for factor Xa, except that the substrate is succinyl-Ala-Ala-Ala-p-nitroanilide (Calbiochem-Nova Biochem Corp.; San Diego Calif.) and the enzyme is human neutrophil elastase (Athens Research and Technology, Inc.; Athens Ga.). The enzyme concentration is 75 nM and the substrate concentration is 600 xcexcM. The control compound is xe2x80x9cTENSTOPxe2x80x9d (N(xcex1)-tosyl-Gly-p-amidinophenylalanine methyl ester; American Diagnostica, Inc.; Greenwish Conn.), which is a reversible factor Xa inhibitor (Sturzebecher et al., Thromb. Res. 54 (1989), 245-252; Hauptmann et al., Thromb. Haem. 63 (1990), 220-223, each of which is incorporated herein by reference).
Test 2: Assays for Determining Inhibition of Coagulation
The effectiveness of the compounds of the formula I may be assessed by the in vitro prothrombin time (PT) assay using pooled human donor plasma. An ex vivo assay may also be used in which plasma is collected at various times after intravenous (iv) administration of a compound of the formula I to rats or to rabbits, or after intraduodenal (id) administration to rats, and analysis using the PT assay to determine plasma half-life. The PT assay is initiated with a thromboplastin dilution selected to obtain an extended and highly reproducible coagulation endpoint, referred to as the xe2x80x9cdilute PT assayxe2x80x9d as described below. The effectiveness of the compounds may also be determined using an in vivo rat arteriovenous shunt model of thrombosis.
a. In Vitro Dilute Prothrombin Time Assay
100 xcexcl prewarmed (37xc2x0 C.) pooled human platelet poor plasma (PPP) is added to a fibrometer cup (Baxter Diagnostics, Inc.; McGaw Park Ill.). 50 xcexcl of various concentrations of a compound of the formula I in TBS-BSA with calcium (50 mM Tris-Cl, 100 mM NaCl, 0.1% (w/v) bovine serum albumin (BSA), 20 mM CaCl2) is added. In control experiments, TBS-BSA with calcium but without a test compound of the formula I is added for measurement of uninhibited coagulation time. 150 xcexcl diluted prewarmed rabbit thromboplastin (Baxter) with calcium is added to the fibrometer cup and the fibrometer timer is started. A rabbit thromboplastin dilution curve is obtained prior to treating the compound and is used to choose a thromboplastin dilution that allows approximately 30 sec PT time for uninhibited controls. The experimental concentration giving 50% inhibition of coagulation (EC50) is calculated from the dilution curve times.
Alternatively, the dilute prothrombin time assay may be conducted using the xe2x80x9cresearchxe2x80x9d mode on an Instrumentation Laboratories (IL) ACL3000-plus automated coagulation instrument (IL; Milan, Italy). Thromboplastin is diluted until a clotting time of 30-35 seconds is achieved. This clotting time is taken as 100% activity. A standard curve for calibration is established by serial 2-fold dilution of the diluted thromboplastin reagent (rabbit brain IL-brand thromboplastin). During the assay, a 50 xcexcl sample (plasma separated by centrifugation) is mixed with 100 xcexcl thromboplastin reagent and nephelometric readings are taken over 169 sec. Coagulation time is determined from the maximal rate of change of light scatter calculated by the instrument. Inhibition is expressed as percent activity as determined by comparison with the calibration curve.
b. Ex Vivo Dilute Prothrombin Time Assay
A test compound of the formula I is administered iv either through the tail vein (rat) or ear vein (rabbit) following an approved protocol. Blood samples of 1 ml volume are removed at timed intervals after administration of the test compound from a cannulated carotid artery (rat) or auricular artery (rabbit). After centrifugation to obtain PPP, the plasma is immediately stored on ice or frozen.
For dilute prothrombin time determination, the plasma is prewarmed and assayed as described above. Percent inhibition is calculated from a thromboplastin dilution curve, which is run with each series of samples, and used to determine the time at which approximately 50% of the initial anticoagulant activity remains in the plasma (Txc2xd).
The test compound of the formula I may also be administered to rats using an intraduodenal dosing protocol. Male Sprague-Dawley rats weighing approximately 300 g are anesthetized with a combination of ketamine/xylazine administered subcutaneously, following an approved protocol. The right carotid artery is cannulated for blood sampling. A laparotomy is performed and the duodenum is cannulated with a ball-tip needle and tied into place to ensure that the suture is distal to the point of insertion. An additional tie is placed proximal to the insertion point to prevent leakage of gastric contents. The effectiveness of the suture in preventing a compound from reaching the site of insertion is tested by pressure testing at the conclusion of each experiment. The point of insertion is approximately 4 cm from the duodenal-gastric junction. The compound is administered in 1 ml normal saline. A blood sample of 0.7 ml is drawn prior to administration of the test compound of the formula I and at 15, 30, 60, 90 and 120 min after administration. The plasma is separated by centrifugation and assayed for inhibition of coagulation using the dilute prothrombin time assay.
c. Rat Arteriovenous Shunt Model of Thrombosis
The anti-thrombotic efficacy of the compounds of the invention may be assessed using rat extracorporeal arteriovenous (AV) shunt. The AV shunt circuit consists of a 20 cm length of polyethylene (PE) 60 tubing inserted into the right carotid artery, a 6 cm length of PE 160 tubing containing a 6.5 cm length of mercerized cotton thread (5 cm exposed to blood flow), and a second length of PE 60 tubing (20 cm) completing the circuit into the left jugular vein. The entire circuit is filled with normal saline prior to insertion.
A test compound of the formula I is administered by continuous infusion into the tail vein using a syringe pump and butterfly catheter (infusion volume 1.02 ml/hr). The compound is administered for 30 min, then the shunt is opened and blood allowed to flow for a period of 15 min (total of 45 min infusion). At the end of the 15 min period, the shunt is clamped and the thread is carefully removed and weighed on an analytical balance. Percent inhibition of thrombus formation is calculated using the thrombus weight obtained from control rats, which are infused with saline.
In Table 1 some inhibition constants Ki for factor Xa inhibition by example compounds of the present invention are given. The inhibition constants were determined as described above (Test 1, a., Factor Xa Assay).
As used herein, the following terms have the indicated meanings: xe2x80x9cgxe2x80x9d refers to grams; xe2x80x9cmmolxe2x80x9d refers to millimoles; xe2x80x9cmMxe2x80x9d refers to millimolar; xe2x80x9cmlxe2x80x9d refers to milliliters; xe2x80x9cm.p.xe2x80x9d refers to melting point; xe2x80x9cdec.xe2x80x9d refers to decomposition; xe2x80x9cxc2x0 C.xe2x80x9d refers to degrees Celsius; xe2x80x9cxcexclxe2x80x9d refers to microliters; xe2x80x9cnMxe2x80x9d refers to nanomolar and xe2x80x9cxcexcMxe2x80x9d refers to micromolar.